Frequently asked questions

Below, you will find answers to frequently asked questions about DKMS, bone marrow and blood stem cell donation, transplants, and fundraising efforts.
About DKMS

What does the abbreviation DKMS stand for?

DKMS stands for ‘Deutsche Knochenmarkspenderdatei’, or German Bone Marrow Donor Center. But as we grew internationally and extended our mission to include the United States, Poland, the United Kingdom, Chile, India, and South Africa, we moved to give ourselves a standard identity. In 2016 we decided to use the same name everywhere – DKMS – to make us identifiable as a single organization that operates under a single name.

If you registered before 2016, you may have registered with Delete Blood Cancer. Everyone who registered with Delete Blood Cancer remains on file with DKMS and on the national registry. While we have rebranded most of our materials to reflect our new name, you may still encounter our Delete Blood Cancer name in our email addresses and on other materials.

I registered with Delete Blood Cancer. What is DKMS?

In 2016, Delete Blood Cancer DKMS changed its name to DKMS as part of a global rebranding of DKMS offices around the world. Everyone who registered with Delete Blood Cancer remains on file with DKMS and on the national registry. While we have rebranded most of our materials to reflect our new name, you may still encounter our Delete Blood Cancer name in our email addresses and on other materials.

What is DKMS' nonprofit status?

DKMS is classified by the Internal Revenue Service as a nonprofit 501(c)(3) organization and a 509(a)(1) public charity. We are exempt from federal income tax and all contributions made to our organization are tax-deductible to the extent allowable by law. A copy of the IRS letter of determination declaring our tax-exempt status is available upon request and you can click here to see our full financial disclosure.

DKMS careers

DKMS is an international nonprofit organization committed to the fight against blood cancer. Our mission is to give as many patients as possible a second chance at life.

We are always looking for the best possible people to join our team! Get inspired by doing something that really matters and join our team of dedicated, caring people at DKMS. Every day, we help save lives by adding more potential donors to the bone marrow registry and connecting patients in need of a transplant with matching donors who can make it happen. Globally, we've registered more than 9 million potential donors, and more than 70,000 of these have gone on to donate to patients. You’ll be part of a growing international nonprofit where creativity, initiative, compassion, collaboration, and strategic thinking are rewarded as we work together to expand our reach, recruit more donors and help save more lives.

Learn more about available openings here.

What qualifications do I need to work for DKMS? What kind of professionals are they looking for?

DKMS offers a wide range of job opportunities at its various sites across the United States, Germany, the United Kingdom, India, Poland, Chile, and South Africa. We need employees for various medical positions, such as medical laboratory assistants, biologists, and doctors, but also for a host of other positions that require only basic medical knowledge. In addition, we need qualified staff for our IT, accounting, administration, marketing, fundraising & events, and press departments.

Since 2011, DKMS has been offering traineeships for various professions as well.

General questions

I have new contact information. How do I update my personal details?

Right here on our website or by phone. Call us on 212-209-6700 or click here to update your information.

Why do I need my DKMS donor ID card?

After you swab your cheeks and return your swab kit, our lab receives them for typing. Once this process is complete you will be issued a DKMS donor ID card. This will come in the mail along with a letter confirming that you are in fact a registered lifesaver.

On the card, you will find your personal donor ID number. Please keep your donor card handy so that, if you ever need to contact us, you will have this information on hand.

What is blood cancer/leukemia?

'Blood cancer' is the umbrella term used for a variety of malignant diseases of the blood-forming (hematopoietic) system. A distinction is made between two kinds, depending on how they originated: leukemias and lymphomas. Leukemias begin in the bone marrow, whereas lymphomas start in the lymphatic system. All blood cancers involve the degeneration of certain blood cells, which multiply uncontrollably and suppress the healthy blood-forming system. This prevents the blood from performing vital functions, such as fighting infections, transporting oxygen or stopping bleeding.

The three most common forms of blood cancer are:

What is the quality of the DKMS typing?

HLA characteristics are the most important factor in identifying a matching donor. In order for a stem cell transplantation to have the highest chance of success, ideally 10 out of 10 relevant HLA characteristics should match between the patient and the donor. If a patient is fortunate enough to have several matches, other factors will be analyzed to find the optimal match. This is why we test more than 10 HLA characteristics. As part of the initial typing, we also tissue type for further parameters that could prove advantageous, either now or in the future, such as the entire KIR receptor family, MICA/B, CCR5, HLA-DPB1, HLA-E, HLA-DQA1, HLA-DPA1, HLA-DRB3/4/5 and the ABO and Rh blood groups. In addition, our donors are also tested for cytomegalovirus (CMV), a common herpes virus. All of these markers are currently typed at high-resolution when someone registers as a donor.

At DKMS, we use cutting-edge science to continuously expand the typing profiles of donors and to meet or define state-of-the-art standards in technology and medicine. That way, we ensure constant enhancements and even more precision in donor selection. All of these quality improvements are crucial for the benefit of patients.

All the samples we receive are typed at the DKMS Life Science Lab located in Dresden, Germany. The lab is a world leader in HLA diagnostics and accredited to international standards. In 2013, the DKMS Life Science Lab became the first HLA-typing lab in the world to introduce the new sequencing technology NGS (Next Generation Sequencing), for high-parallel, high-throughput typing.

Do ancestry and ethnicity affect matching?

Tissue characteristics vary from person to person – but they are also different between ethnicities. So when it comes to finding a matching donor, a person’s ethnic background is important. Blood cancer, on the other hand, can happen to anyone. So we need as many people as possible with the widest possible variety of genetic characteristics to register in our database. A donor with the same ethnic background as a patient may be a better match than one who comes from an entirely different background.

If you register with DKMS as a potential blood stem cell donor, one of the questions we ask you will be about your ethnic background. This information allows us to better organize our database and makes it easier and faster for doctors to search for a matching donor for their patients.

Does a donor have to have the same blood type as the patient?

For blood stem cell and bone marrow transplants, what matters is the best possible match between the human leukocyte antigen (HLA) tissue characteristics from the donor and patient. A perfect match is very complicated to find.

Doctors generally look at 10 specific HLA markers to determine a match. Most require at least a 9 out of 10 match, but a 10 out of 10 is best. The closer the match, the better the chances that the patient’s immune system will recognize donated cells as its own and allow them to grow and make new healthy blood cells. When blood stem cells are transplanted, the recipient acquires the same blood group as the donor.

Swabbing is the test used to see if you are a matching bone marrow donor for any patient in need. When you sign up, we send you a buccal swab kit, you swab your cheeks, then send it back to us. Once we receive it, it goes to our lab for processing and then you are added to the National Bone Marrow Registry. Once on the registry, you are put on standby until you are a match for a patient in need.

How do I know that my data is secure?

As the world’s largest network of blood stem cell donor centers, DKMS has a special responsibility to protect the personal and especially sensitive medical data that registered donors entrust to us. We take data privacy very seriously. It goes without saying that we fully comply with all statutory requirements, but we have also committed to an even higher level of data privacy.

Your personal details are only handled by DKMS and our appointed service providers. Our commissioned data processing (CDP) agreements with service providers ensure they are all committed to upholding our highest data privacy standards. The data relevant to the stem cell donor search, such as HLA tissue characteristics, age, and gender, is always pseudonymized before we send it to other German and international search registers, such as the German National Bone Marrow Donor Registry (ZKRD) and the National Marrow Donor Program in the US (NMDP). This means that doctors and transplant centers searching the database for a matching donor are only able to see this information and your personal information remains only with DKMS.

At DKMS, we are committed to treating and using health information we may gather about you responsibly. This Notice of Privacy Practices (this “Notice”) describes the personal and health-related information we collect, and how and when we use or disclose that information. It also describes your rights with respect to such information. This Notice was last updated on May 26, 2020.


DKMS does not provide any medical services; however, we recruit healthy volunteers as potential hematopoietic stem cell (HPC) donors, and we facilitate medical services for the donation process. The information we gather helps hospitals that treat patients with life-threatening blood diseases make treatment decisions for their patients.

Our marketing and field-based recruitment teams may store and use information about patients and families with whom they have relationships, for example in connection with follow-up stories regarding those patients. Such information will only be used in accordance with the terms of this Notice. DKMS considers those who register to be potential donors to be “registrants,” and those who begin any part of the donation process to be “donors.” As a registrant, we obtain information from you such as your name, date of birth, gender, social security number, address, telephone numbers, email address, ethnicity and ancestry, family contact information and banking information (if you decide to donate to our cause). DKMS stores this information, and may share such information amongst its affiliated entities, some of which may be located outside of the United States. As a donor, each time you visit a doctor, hospital, laboratory, or any other health care provider, a record of your visit is made. Typically, this record contains your name, age, gender, address, telephone number, symptoms, examination and test results, and, if needed, a diagnosis, treatment, and plan for future care. Additionally, we store basic information about transplant recipients that is needed to facilitate HPC donations. This information, often referred to as your health or medical record, serves as a:

• Basis for planning your donation in a way that minimizes donor risk, and delivering HPC products to benefit transplant recipients.
• Means of communication among the many health professionals who contribute to your care and the treatment of patients.
• Legal document describing the care you received.
• Means by which you, DKMS, or a third-party payer can verify that services were actually provided.
• A source of data for medical research.
• A source of information for public health officials as required by local or federal law.
• A source of data for our planning and marketing.
• A tool with which we can assess and continually work to improve the care we render and the outcomes we achieve.

Understanding what is in your record and how your health information is used helps you to: ensure its accuracy, better understand who, what, when, where, and why others may access your health information, and make more informed decisions when authorizing disclosure to others.

What is the DKMS Life Science Lab?

Based in Dresden, Germany, the DKMS Life Science Lab GmbH (LSL) is one of the world’s largest and most advanced genotyping laboratories focusing on high-resolution HLA typing for stem cell donor registers. Over 100,000 donor samples a month can be analyzed there.

From the outset, LSL has aimed to incorporate the latest scientific findings and developments into the standard typing process. This has led to the typing profile being extended beyond the standard HLA characteristics to include numerous additional parameters (e.g. ABO, RhD, CCR5, KIR, HLA-E, MICA/B, and CMV IgG).

When fast action is needed, this is the best and quickest way to check whether – and how well – a potential blood stem cell donor matches a blood cancer patient. Thanks to our high-quality typing, search times have decreased, while the chances of a successful transplant have increased.

The DKMS Life Science Lab employs cutting-edge biotechnology procedures. In 2013, for instance, it was the first HLA-typing laboratory in the world to introduce the new NGS technology (Next Generation Sequencing), for high-throughput typing. Today, well over a million potential blood stem cell donors a year are typed using this procedure.

Attached to the DKMS Life Science Lab are a clinical laboratory for patient-based typing or confirmatory typing (CT), and a clinical search unit accredited by the ZKRD (German National Bone Marrow Donor Registry). For more information please visit

Eligibility and registration

I am - or I think I am - already registered with another donor center. Should I register with DKMS as well?

We ask that all who wish to register must be confident that they are NOT registered with DKMS or any other U.S. organization that registers bone marrow donors. Multiple registrations by the same individual can result in duplicate HLA profiles searchable on the National Bone Marrow Donor registry.

If you wish to register with DKMS but are not sure if you are already registered, please first contact the Be The Match registry by calling 1-800-MARROW2 (1-800-627-7692). If you are not registered with them, you are invited to contact DKMS to ensure you’ve never registered with us, either. If you have not, we’ll gladly add you to our lifesaving team!

Who can register as a potential blood stem cell donor?

If you are between the ages of 18 and 55-years-old and in general good health, then you may be able to register as a blood stem cell donor.

If you have previously registered with DKMS or another donor center, there is no need to do so again, as you will already be available for searches worldwide. If you have been diagnosed with any chronic or serious illnesses (whether current or in the past), please check with us before signing up.

The National Marrow Donor Program has established medical guidelines that we follow to protect the safety of the donor. The following medical conditions would prevent a person from registering as a donor or from being cleared to donate.

  • HIV
  • History of heart surgery or heart disease
  • Autoimmune disorders such as lupus, rheumatoid arthritis or multiple sclerosis
  • Fibromyalgia
  • Factor V
  • Sleep apnea, breathing problems or severe asthma (daily inhalers are acceptable)
  • Diabetes requiring insulin or injectable medication
  • Hepatitis B or C
  • Kidney or liver disease
  • History of stroke, including TIA
  • Multiple concussions or head injuries
  • Chronic or severe neck or back problems
  • Epilepsy or other seizure within one year
  • History of blood clotting or bleeding disorders
  • Personal history of cancer (exceptions: Stage 0 or in situ melanoma, breast, bladder, cervical and cured localized skin cancer such as basal cell or squamous cell carcinoma)

Who is NOT ABLE TO register as a blood stem cell donor?

Although we wish everyone could be a donor, there are some medical conditions that have been determined as making a person ineligible to register or donate.
Body mass index (BMI) less than 40 (BMI=weight/height²)

To register with us or to donate blood stem cells, your body mass index (BMI) must not be over 40 – for various reasons.

For people in general good health, donating blood stem cells does not have any significant risks. However, for people with additional risk factors, there may be some health concerns. Unfortunately, obesity is one such risk factor.

Severe obesity poses a problem because it leads to a degree of risk for the donor with both types of blood stem cell collection procedures. Not only is the anesthetic risk higher with bone marrow donations, but with peripheral blood stem cell collection, it is also difficult to gauge precisely how much medication is needed, which may increase the chances of side-effects.

The health and safety of our donors is our number one priority and the weight limits are in place purely for the protection of our donors.

Systemic autoimmune diseases or other serious chronic diseases (e.g. diabetes, rheumatism)

If you have diabetes mellitus type 1, registering as a potential donor is unfortunately not possible due to health concerns for both you and the potential recipient.

Blood stem cells are a part of the immune system, which means that a donation from a type 1 diabetic could mean that the condition is passed on to the recipient. As the patient’s health is already compromised, it is difficult to predict how their condition might develop. Serious complications would be likely to occur.

In addition, increased blood sugar levels may already have damaged the donor’s nerves and blood vessels to varying degrees, and donating blood stem cells could compromise their health even further.

With diabetes mellitus type II, or type 2 diabetes, some cells become resistant to insulin. This prevents them from absorbing sufficient glucose from the bloodstream. Increased blood sugar levels may already have damaged nerves and blood vessels to varying degrees. Donating blood stem cells could compromise their health even further – so again, we cannot include anyone with type 2 diabetes as a potential blood stem cell donor.

Rheumatoid conditions, even when there are no symptoms, are another factor preventing people from registering. They include rheumatoid arthritis, Bekhterev’s disease, and juvenile arthritis, all of which are autoimmune diseases and therefore mean that unfortunately, you cannot register as a blood stem cell donor.

A stem cell transplant involves the transfer of cells from the immune system, and if the donor’s immune system is damaged, it will have adverse effects on the recipient, compromising their health.


(including former patients who have been given the all-clear)
Unfortunately, anyone who has previously had a malignant condition is not able to donate blood stem cells.

If you have ever had a malignant growth (or, to be more precise, one that is not specifically benign) you cannot donate blood or stem cells — no matter how long ago the illness was or how successful the therapy was.


(alcohol, drugs, medications)

Occasional marijuana/cannabis consumption is not an issue – although the emphasis here is on the word ‘occasional’.

This is in part because regular drug use raises the question of reliability. It is not that a donor who takes drugs would be any more likely to suffer any complications, but unreliability is extremely problematic. The timing and scheduling of blood stem cell donations and transplants is crucial to the survival chances of the patient.

For you to register, we need to know what drugs you take and for how long you have been taking them. If you have been consuming them for a long time, it might be better not to register, but if you are ready and able to quit, then you are welcome to join us as a potential blood stem cell donor.

Severe cardiovascular diseases

High blood pressure that is successfully regulated or a mitral valve prolapse with no further symptoms do not affect your ability to become a blood stem cell donor. The same goes for people with an unusually high or low resting pulse rate: as long as it is regular, that is all that matters.

However, with most other cardiovascular conditions, requiring treatment or monitoring, the risk of complications when donating blood stem cells is significantly higher. This means that anyone suffering from conditions such as cardiac arrhythmia, damaged vascular walls, arteriosclerosis (especially if blood thinners are needed), heart attacks, strokes, or structural damage to the heart (such as valve defects) is not able to register as a potential blood stem cell donor.

Another factor that would definitely prevent you from donating blood stem cells is frequent or prolonged breathlessness.

If you are being treated for any other conditions, please contact us to check if you can still become a blood stem cell donor.

Factor V Leiden

Due to potential health risks for both the donor and recipient, individuals with Factor V Leiden mutations (heterozygous or homozygous) are ineligible to contribute stem cells to our registry.

HIV, hepatitis B or C, syphilis

If you have a serious, life-threatening infection such as HIV and if there is no way of proving that you are fully cured (e.g. hepatitis C), we cannot allow you to donate blood stem cells, primarily for the protection of the recipient.

Disorders of the blood or immune system

Disorders of the blood and immune system are problematic because blood stem cells for transplantation come from the blood-forming and immune systems. To minimize the risk to recipients, both of these systems should be working as normally as possible. When blood stem cells are transplanted, acquired disorders can potentially be transplanted with them, as the cells for transplant contain mature cells of the immune system. In addition, some blood disorders can pose an increased risk to the donor: problems with clotting factors, for example, can cause thrombosis or bleeding.

Can I register for a specific person?

No. When you register with DKMS, you are added to the national registry where any patient searching for a donor can potentially match with you. Registering is a serious commitment that requires you to be willing to donate to any patient in need. If you only want to see if you can donate to a particular person, you must be tested privately through the patient’s transplant doctor.

What if I am pregnant – or become pregnant?

You can register as a potential blood stem cell donor even if you are pregnant, as long as you meet all of the other requirements. Please let us know if you are pregnant and when your due date is.

You will be blocked from donor searches during your pregnancy, until six months after your due date. After that, we will include you in searches again unless you instruct us otherwise.

Can I register as a donor if I’m part of the LGBTQ community?

Sexual orientation does not make people ineligible to register as a potential bone marrow or blood stem cell donors and it is not part of our eligibility criteria. Instead of screening potential registrants for past sexual encounters, we make sure that ALL of our donors have a medical examination before donation to see if they are in good health.

What are the chances I'll get called to donate?

You could be called as a potential match within weeks of registering. Or, perhaps it will take years. There is a chance that you may never be called, but there is also the chance that, if you do get called, you are the ONLY one who can save that patient’s life.

"It's just amazing to me that I can live again. I have one more chance at living – to actually be able to do something." —Darian, transplant recipient and survivor

I registered a long time ago. Do I need to re-swab to stay registered?

No, once you’ve registered and received confirmation that you are in our database and on the national registry, you’re all set. Once registered, you will remain on the registry until age 61, unless you ask to be removed earlier.

I'm over 55. Why can't I register?

The age limit is not meant to discriminate. Medical guidelines have been established to protect the safety of the donor and provide the best possible treatment to the patient. With age comes a small increase in the risk of side effects from anesthesia. Additionally, research shows that cells from younger donors lead to more successful outcomes for patients.

I'm under 18. Why can't I register? Can my parents sign the consent form for me?

18 is the age of legal consent in the U.S. for voluntary medical procedures like bone marrow or blood stem cell donation. A guardian or parent cannot provide consent in these instances.

Why are there weight restrictions for potential donors?

There are medical guidelines for bone marrow donations that have been established by the National Marrow Donor Program (NMDP) to protect the safety of the donor and provide the best possible outcome for the patient. The height and weight guidelines for donors allow for a Body Mass Index (BMI) of up to approximately 40. Possible complications with donors that have a higher BMI include increased risk for anesthesia for bone marrow donation and comprised venous access for PBSC collection.

Why do you ask for a social security number?

Providing your social security number is completely optional and you do not need to provide it.

We ask for it as an additional way for us to locate you if you are a match and we can not reach you at the address, phone number, alternate contact information, or email that you provided. It is not used at any other time for any other reason.

Why do you ask for alternate contact information?

The alternate contact information is only used if there is a patient you have matched with and you cannot be reached. The information is kept private and is never sold or used for any kind of marketing purposes.

Sadly, there have been situations where we couldn't reach a donor and a patient's life was in jeopardy because we did not have their updated contact information. We were able to locate the donor through the alternate contact and a patient was saved!


What is human leukocyte antigen (HLA) typing?

Human leukocyte antigen (HLA) typing is a DNA-based tissue test used to match patients and donors for bone marrow transplants. HLA are proteins — or markers — found on most cells in your body. Your immune system uses these markers to recognize which cells belong in your body and which do not. The closer the match the better the chances the patient’s body will accept the donated cells and allow them to grow and make new healthy cells.

• You inherit half of your HLA markers from your mother and half from your father. This means you and your sibling have a 25% chance of having exactly the same HLA characteristics.

• This also means that most patients – about 7 out of 10 -- are unable to have a donation from a sibling, and an unrelated donor is required. This donor should ideally be a perfect HLA match.

• The more people who register, the better the chances for patients who are waiting for their lifesaving match.

Am I the only match?

It is possible for a patient to find multiple potential matches. However, that information is known only to the patient’s doctor, not to us. The doctor will select the best donor based on how close the HLA match is, as well as the donor's age, sex, health status and history, availability, and other factors. If you are contacted as a potential match but not selected for donation, we will inform you. You will remain on the registry to be available for other searching patients.

How are patients matched with donors?

A cheek cell sample is collected at registration. The sample is tested for the HLA characteristics and added to the global donor pool. Doctors can then search the registry and find a matching donor for their patient by comparing the patient's HLA to the donor's.

What happens if I match with a patient?

More testing will need to be done to determine if you are the best suitable match. This includes completing a health history questionnaire, providing blood samples and undergoing a physical exam. A DKMS representative will walk you through each step of the process and will be available to answer any questions you may have.

Click here to learn more.

What makes a good match?

Doctors generally look at 10 specific HLA markers to determine a match. Most require at least a 9 out of 10 match, but a 10 out of 10 is best. The closer the match, the better the chances that the patient’s immune system will recognize donated cells as its own and allow them to grow and make new healthy blood cells. We generally don’t find out exact patient-donor HLA match ratios.

How long do I have to make a decision?

When you registered as a bone marrow donor, you made a serious commitment. You always have the right to change your mind. However, a late decision to NOT donate can be life-threatening to a patient, so we ask that you consider your decision seriously upon learning you are a potential match. Talk to family, talk to friends, talk to your DKMS coordinator, who can answer all your questions and even connect you with a past donor who can give you firsthand insights into a donation.


How does the search for a bone marrow or blood stem cell donor work?

Looking for a matching stem cell donor is like looking for a needle in a haystack. When a blood cancer or blood disorder patient depends on a blood stem cell transplant to survive, they need a donor whose human leukocyte antigen (HLA) characteristics are a 100 percent match, if possible. The patient's medical team sends a search request to local and international databases. If a potential donor is found to match the patient, the donor center will be informed and the registered donor is contacted immediately.

Four-in-ten patients do not find a matching donor. That is why we need as many people as possible to register as donors.

Peripheral Stem Cell Donation (PBSC)

The most common method of stem cell removal is peripheral stem cell collection (PBSC), which is used in around 80 percent of cases. Here, stem cells are obtained from the blood by a special procedure called apheresis.

Your blood is drawn from one arm and passed through the apheresis machine that filters out the blood stem cells and returns the blood back into your body through the other arm. To increase the number of stem cells in your blood flow at the time of donation, you will receive a 5-day course of a synthetic protein called filgrastim. Filgrastim signals your bone marrow to release more than average amounts of stem cells into your bloodstream.

Peripheral stem cell donation usually takes between four and six hours. Occasionally donors are asked to come back for a second day to complete the donation.

Bone marrow donation

Bone marrow removal is used in about 20 percent of stem cell donations. It is an outpatient surgical procedure performed under general anesthesia.

Doctors use a special syringe to collect a volume of bone marrow, which stores blood stem cells, from the iliac crest of the hip bone. After the procedure, you will be sent to recovery and monitored. Once cleared by the physician, you will be sent home or back to your hotel on the same day. Bone marrow donation is more commonly requested by patients’ medical teams to treat pediatric cancers and certain forms of anemia.

After the bone marrow has been removed, the donor may experience localized pain for a few days. This is caused by the wound and often feels like bruising.

Does a donor get to choose the donation method?

There are two methods of donation – peripheral blood stem cell donation (PBSC) and bone marrow donation.

The patient’s medical team determines what method will provide the best chance for a successful transplant. The most common method, performed in 80% of transplants is PBSC.

We do ask that all registered donors be comfortable moving forward with either procedure. If you become a match for a patient and are not willing to donate through one of these methods, please notify your coordinator immediately.

As a DKMS donor, how am I insured?

All DKMS donors are covered through the National Marrow Donor Program Donor Policy which includes medical, disability, and life insurance. This policy covers donors for all donation related activities as well as travel to and from any donation related activities. *Coverage may be subject to exclusions

Can you donate blood stem cells more than once?

On rare occasions, a donor is asked to donate a second time, either to the same patient or to a different one.

If you have blood stem cells removed, new ones will be generated to replace them, in much the same way as your blood is replaced when you make a blood donation. So it is possible to donate more than once. However, to minimize the strain on donors as far as possible, we try to keep those that have made a donation as backups, just in case their patient has a relapse and more blood stem cells are needed.

Learn more about second donations here.

When I donate, does it mean I will be missing stem cells?

After a blood stem cell donation, the body quickly regenerates the level of blood stem cells to what they were before the donation. The process is comparable to a blood donation and does not lead to a permanent loss of blood stem cells. The donor’s own immune system will not be weakened.

Is the donation painful?

Both donation procedures will result in some level of discomfort, but most donors report that any pain experienced is easily eclipsed by the positive feelings of knowing they are possibly saving a life.

Possible side effects and recovery of peripheral blood stem cell collection (PBSC)
While taking filgrastim, you may experience flu-like symptoms such as headaches, bone and muscle aches and fatigue. Most side effects should subside within 48 hours of donating. Your stem cells replenish within 1 week.

Possible side effects and recovery of bone marrow donation
You may experience some pain, bruising, and stiffness for up to two weeks after donation. Within a week of donating, you should be able to return to work, school and many regular activities. Your marrow will completely replenish itself within 3-6 weeks.

We check up with you regularly after donation to make sure you are recovering properly. If you're not, we'll arrange and pay for any follow-up care.

Is donating marrow or stem cells the same as giving blood?

No. When you register with DKMS, you are making yourself available as a potential marrow donor for a patient in need of a transplant.

If you do match with a patient, you will be asked to donate marrow or blood stem cells in procedures that differ from donating blood. You can remain a regular blood donor after registering as a bone marrow donor, however, if you do match with a patient, we ask that you don’t give blood for a month prior to donation.

Is bone marrow taken from my spine?

In bone marrow donation, marrow is extracted from the back of your pelvic bone - the iliac crest - using a special syringe. This method of donation is only done in 20% of transplants and most often for a pediatric patient.

Learn more about the two methods of donation: peripheral blood stem cell collection (PSBC) and bone marrow donation.

Will I permanently lose my bone marrow or stem cells?

For either donation procedure, the amount of stem cells collected is only a fraction of your body’s total. Your donation does not weaken your immune system and the cells will naturally replenish themselves within a few weeks.

How does a bone marrow or blood stem cell donation work?

Peripheral stem cell donation

In about 80 percent of the cases the stem cells are taken from the bloodstream. The donor is administered the growth factor G-CSF for five days. This drug increases the number of stem cells in the peripheral blood, which are then obtained directly from the blood using a special procedure. The donation takes 4-8 hours on one or two consecutive days. No surgery is necessary, you can usually leave the clinic the same day. This procedure has been used at DKMS since 1996. During the administration of the drug, flu-like symptoms may occur. Long-term side effects are not known according to the current state of research.

Bone marrow donation

In this method, bone marrow is taken from the donor under general anaesthesia using a special syringe from the iliac crest. Two small incisions in the area of the rear pelvic bone are usually sufficient. The resulting wounds are so small that they only require a few stitches or often no stitches at all and heal quickly. The removal is performed in the prone position and takes about 60 minutes. With bone marrow donation, the risk is essentially limited to the anesthetic. About 5 percent of the bone marrow is taken from the iliac crest. Usually, the donor's bone marrow regenerates completely within 2 to 4 weeks. Local wound pain can occur, similar to a contusion. Only in rare cases can there be pain that lasts longer. The stay in the hospital lasts three days in total. In most cases, as a precautionary measure, a sick note is taken for a few days.

The type of withdrawal depends on the health condition of the patient. A donor should be prepared to use both methods.


Will I be compensated for the time I take off from work?

If your employer does not provide paid time off for donation, DKMS has a financial assistance program for lost wages compensation. If you qualify for assistance, your coordinator will give you more information about applying for aid.

Will my donation date change?

Donation depends on both your health and that of the patient. In the time it takes for you to go through testing and the physical exam, the patient’s health can take a turn, delaying or even canceling donation. We will always keep you informed of any changes and continue to accommodate your schedule to the best of our abilities.

Where will I donate?

We work with a number of hospitals across the country. In many cases, we will ask you to travel. We arrange and cover the costs for travel and accommodations. In most cases, you will donate at the same facility where you will have your physical exam.

When will I donate?

In most cases you will be asked to donate 1 to 3 months after the confirmatory blood test. We will always try to give you 3 to 4 weeks notice and accommodate your schedule.

Treating blood cancers and disorders


Most types of blood cancer can first be treated with chemotherapy, the aim of which is to simply destroy the cancer cells. Other forms of treatment can be used as well, such as radiation or antibody therapies, or a blood stem cell transplant.

With chemotherapy, the patient is given cytostatic drugs to inhibit cell division and destroy the cancer cells. The treatment is performed over several cycles, with drugs administered on one or more days followed by a break for the body to recover before the next cycle begins. The drugs can be given in the form of tablets, an injection, or an infusion.

Radiation therapy

Radiation therapy is used to specifically target tumors. The radiation is similar to that in X-rays but considerably higher-energy, which works by damaging the genetic makeup of the cancer cells. This stops them from dividing even further and kills them off. The process also affects healthy cells, but these can regenerate later on.

Antibody therapy

Antibodies are generated by immune cells in the body. They work by recognizing surface structures (antigens) of pathogens and attaching themselves to them. Any cells that are flagged in this way are identified by other immune cells as hostile and destroyed. More and more blood cancers can now be treated with artificially produced antibodies — especially non-Hodgkin lymphoma (NHL), but also chronic lymphocytic leukemia (CLL). They work on the basis of a 'lock and key' principle: the available antibodies are the key and work only on cancer cells with a matching lock, or antigen. If lock and key don’t match, the therapy will not work.

Blood stem cell and bone marrow transplant

For many patients, a blood stem cell or bone marrow transplant is their last chance to beat blood cancer. These patients need a matching donor whose tissue characteristics (HLA characteristics) should match those of the patient 100 percent, if possible. To prepare for the transplant, the patient undergoes chemotherapy to suppress their own immune system, which helps to ensure the body does not reject the donation. After the transplant, the immune system gradually rebuilds itself.

Whether or not a patient can undergo a blood stem cell transplant and what method would be used, depends on numerous factors including their particular diagnosis, age, and state of health.

There are three different types of transplant: autologous, allogeneic, and syngeneic.

An autologous blood stem cell transplant uses the patient’s own stem cells, which are harvested from the blood and cleared of cancer cells. The patient is given chemotherapy, and their stem cells are returned to the body.

An allogeneic stem cell transplant uses the blood stem cells of a related or unrelated donor with the closest possible match of tissue characteristics.

A syngeneic transplant is the rarest form of stem cell transplant, as it involves using the cells of identical twins.

Matching donor

One crucial factor in the success of a blood stem cell transplant is the degree of match between the tissue characteristics (HLA) of donor and patient. Tissue characteristics are protein structures on the surfaces of all cells and occur in different combinations in every individual, much like fingerprints. The immune system recognizes from these protein structures whether or not a cell belongs to its own body. If it does, the cell is left intact. If not, it is destroyed. That is why it is essential to find a donor whose HLA characteristics match the patient’s as closely as possible. This way, the new immune system that develops from the donor’s stem cells will accept the patient’s own cells.

Because tissue characteristics are inherited, the best chance of finding a match between donor and patient is within families. Parents are normally only haploidentical, or ‘half-matching’ donors, as a child inherits half of its tissue characteristics from the mother and half from the father. The highest probability of a match is between siblings, which is why they are the first family members to be tested as potential donors.

If there are no matching donors in the patient’s family, the search continues with an attempt to find a compatible unrelated donor. Around the world, over 36 million people have now chosen to register as potential blood stem cell donors, over 10 million of whom are within DKMS’s worldwide database. If no suitable donor is found there, the search is extended internationally.

What diseases do bone marrow and blood stem cells treat?

Bone marrow transplants can be the best or only treatment for patients fighting blood cancers like leukemia, lymphoma and myeloma, as well as approximately 70 other conditions including sickle cell disease, severe aplastic anemia, immune system disorders and inherited metabolic disorders. Nearly 20,000 Americans need bone marrow transplants every year (Source: U.S. Dept. of Health & Human Services based on data from NMDP).

Patients’ questions

A friend or relative needs a transplant. How can I help?

Learning that a loved one may need a bone marrow transplant can be an overwhelming moment. Close friends and relatives of the patient want to help, but don’t always know what they can do. DKMS provides a positive way to get involved: organizing bone marrow donor registration drives to search for donors, rally community support and connect families that are spread across the country. We’ll support your efforts with social media campaigns to create a movement behind your cause. To learn more about the support we can provide you, please contact us at or at 1-866-340-3567.

How can DKMS help me find a matching donor?

The DKMS Patient Engagement Team has many initiatives and programs to support patients in need of a matching donor. Our COVID-friendly registration efforts include a virtual drive platform, drive-thru donor drives, swab kits mailed in tote bags for small-scale in-person efforts, opportunities for outreach through media (TV, radio, newspaper, magazines, social media channels), engagement with our international DKMS entities (Germany, UK, India, Chile, Poland and South Africa), as well as partnerships with other non-profit organizations and patient advocacy groups.

DKMS also offers a free family typing program to type siblings, children and parents of patients in need of a transplant, regardless of age, location or patient’s health insurance status. You can reach the Patient Engagement Team by emailing

I have family and friends who only want to be tested for me, is that possible?

All DKMS potential donors are part of the global donor pool and can be called to save the life of any patient searching for a matching donor. Your donor was likely inspired to join the registry because of another patient’s story. We hope that your journey inspires your family, friends, and community to be available for you and other patients like you.

If your friends and family want to be tested for only you, you can speak with your medical team about testing.

As a blood cancer/blood disease patient, can I be connected with other patients who are also in search of a donor?

DKMS has a private Facebook group to allow our patients and their loved ones to connect, share experiences, ask questions, and feel a greater sense of community. Email to learn more and join our Facebook group.

I have a donor or already received a transplant, how can I help other patients still in need?

The DKMS Patient Engagement Team has created an Ambassador Program to work closely with past patients, caregivers, and donors to share their stories to inspire others, answer questions for newly diagnosed patients, and provide DKMS resources to support a patient’s journey back to health.

Financial questions

If I donate money, will I get a receipt/confirmation?

Yes. When you provide a valid email at the time of making a gift, you will receive a digital receipt that you can save or print out for your records. You may also request to receive a receipt via U.S. mail by contacting or calling 212-209-6760.

Why should I donate to DKMS?

Your $45 helps to register more potential donors. As a non-government funded organization, we rely solely on contributions from individuals, foundations, and corporations to cover these costs and keep registration free for all who are willing to save a life. 100% of all gifts go directly to fund our lifesaving mission.

Who pays for the stem cell or bone marrow donation?

The patient's insurance generally covers the cost of the donation procedure or related testing or doctor's appointments. There is no cost to the bone marrow donor to donate, nor is there a cost to sign up. DKMS covers any transportation costs that the donor might need to get to the transplant center.

To learn more about what happens when you are a match, visit

General coronavirus FAQs

How will DKMS maintain the safety of donors?

The health and safety of our donors is our highest priority. We will consider the circumstances of all of our donors who are asked to donate their bone marrow and blood stem cells, on an individual basis, especially regarding their travel to a collection center. Please be reassured that we provide the best and safest solution possible for our donors.

Unfortunately, donors who live in high-risk areas have to be blocked for search requests, as they are currently not eligible to proceed with a donation. We also have implemented screening for the COVID-19 virus risks before entry to any collection center and before the start of a donation. These measures serve to protect the donor as well as the recipient and the employees in the collection centers. Health experts have confirmed that there is currently no evidence that the novel Coronavirus can be transmitted via blood, bone marrow, or stem cell products.

Please also understand that any planned collection may be postponed or canceled due to the current situation. We will keep you informed about all developments. Regarding the transport of blood stem cell products to the respective transplant clinics, we are in regular and close contact with all parties involved as well as with all relevant national and international authorities and organizations to ensure that all blood stem cell collections can reach the patients.

Is it still safe for patients to receive a transplant?

Health experts have confirmed that there is currently no evidence that the novel Coronavirus can be transmitted via blood, bone marrow, or stem cell products.

How is the transport of collections from donors impacted by the current travel restrictions?

The majority of blood stem cell collections from DKMS donors travel across borders to patients in other countries. Due to the travel restrictions imposed by many countries, we are in regular and close contact with all parties involved in the transport, as well as with the relevant national and international authorities and organizations. Despite the added difficulties that we are facing at the moment, we are, as always, determined to overcome all barriers in order to provide as many patients as possible with a second chance at life.

If I am a potential donor and I have questions, who should I contact?

If you have been contacted by DKMS as a potential donor and if you have any questions or concerns, you are encouraged to contact your DKMS coordinator. As always, DKMS staff is there to help you through the process and answer any questions that you may have.

Can donors postpone their donation at this time?

The final decision to donate is always made by the actual donor. If you have been asked to donate and have any concerns, please contact your DKMS coordinator. We evaluate each case on an individual basis to find the best solution for all parties involved.

Coronavirus FAQs for donors

With the current COVID-19 measures, do hospitals and other medical facilities have the capacity to perform bone marrow and blood stem cell collections? Are these considered essential procedures?

As is the case with every health care institution worldwide, DKMS and all its partners are facing challenges caused by COVID-19. Due to possible staff shortages or an increasing need for ventilators for patients with COVID-19, capacities for blood stem cell collections may be lower than normal. However, we are prepared for this potential situation and will do everything that we can, together with our outstanding team of donors and employees, to provide every patient in need of a blood stem cell transplant with a second chance at life.

What if I am diagnosed with COVID-19 or experiencing symptoms, am I allowed to donate?

If you have a confirmed COVID-19 infection or experiencing COVID-19 symptoms, please inform your DKMS Case Manager as soon as possible.

I am a medical professional and risk possible infection day in and day out. Can I still move forward with the donation process?

If you have a higher risk of being exposed to the COVID-19 virus due to your occupation, for example if you are a health professional or a cashier, you can still move forward with the donation process. However, it is important to inform your DKMS Case Manager or the Collection Center as soon as possible in case you develop any symptoms such as a cough, sore throat, shortness of breath, fever, headache and/or limb pain or in case you have been in close contact with a someone who has been confirmed to have or is suspected of having COVID-19. If you work in a medical field that is essential during the current pandemic, such as ICU, and/or cannot be absent from work due to healthcare staff shortages, please inform your DKMS Case Manager to find the best possible solution.

Will there be any additional screenings?

Before Physical Examination: DKMS has implemented screening for COVID-19 risks. The DKMS Case Manager will discuss any possible symptoms with donors. Additionally, donors receive an information sheet and are asked to actively and immediately inform their Case Manager or the collection center if necessary.

During/after Physical Examination: Before entry to collection centers and before the start of a donation, the collection centers have implemented screening for COVID-19 risks. All donors will have a risk history check before entering the collection center. If this shows that the donor could potentially be infected with COVID-19, a test for the COVID-19 virus will be carried out. These are the questions of the risk anamnesis:

  • Are you currently experiencing any symptoms of a respiratory infection such as a cough, sore throat, shortness of breath, fever, headache and aching limbs?
  • Have you been or are you ill with COVID-19 or have you tested positive for the COVID-19 virus?
  • Have you been in contact with someone who has been diagnosed with COVID-19 or a suspected case in the last 4 weeks?
  • Have you been abroad in the last 4 weeks?

How will the donation process affect my immune system?

The health and well-being of our donors is our number one priority. We conduct a medical long-term observation of our donors to identify any potential adverse reactions to a blood stem cell donation. So far, a relevant immunodeficiency as a result of a blood stem cell or bone marrow donation has not been proven.

Will I be able to bring someone along for the day of donation?

Unfortunately, accompanying persons are currently not allowed to enter the collection center. This is for your own safety as well as the protection of staff and other donors.

Is it safe for the patient to receive a transplant during the pandemic?

The COVID-19 pandemic is greatly impacting patient care. Transplant centers are reassessing treatment timeframes for all patients as a way to mitigate the heightened risk of infection. Patients in stable condition with slower progressing diseases may be able to postpone their transplants to later in the year. However, for many patients with more aggressive diseases, such as acute myeloid leukemia, transplant delays are not an option. As a result, transplant centers are exploring other stem cell sources like cord blood and haplo-transplant. This may still not be a viable option for many patients. There is no evidence suggesting that COVID-19 can be transmitted through blood. Therefore, we will continue to work with donor matches to help every patient in need. We are committed to supporting our donors in making a decision with which they feel both confident and comfortable.

I am concerned about traveling for donation. What can I do to protect myself?

We understand you may be concerned about travel and exposing yourself to potential risks. We strictly follow the CDC guidelines when arranging your travels. If traveling for donation will affect your ability to return to work or other duties, please let us know right away. We will look for alternative options for your donation. However, due to the limited capacities at medical centers at this time, donors may be asked to consider driving a 5-6 hour distance to another state. These are some options we will discuss with you before making the final decision. You can find additional information on risk locations and travel recommendations on the CDC website.

If you feel uncomfortable traveling, we respect your decision. However, it is extremely important that you tell us right way so we can explore other options. Donation is time-sensitive, and any delay can have a negative impact on the recipient’s wellbeing.

Should I wear a mask during my travels, appointments, and the donation itself?

Masks can help protect you and others from COVID-19. As per CDC recommendations, layered prevention strategies — like staying up to date on vaccines and wearing masks — can help prevent severe illness and reduce the potential for strain on the healthcare system. The purpose of this is to protect from the spread and limit exposure to COVID-19. COVID-19 Community Levels are a tool to help communities decide what prevention steps to take based on the latest data. Find community levels and prevention steps by county via the CDC website.

What is cryopreservation of stem cells and why is it being recommended for my donation?

Cryopreservation is the freezing of stem cells. After your donation, your cells will be sent to your recipient’s transplant center. The transplant center will freeze and store your cells until the recipient is ready for transplant. Because travel and logistics recommendations are changing rapidly, the Nation Marrow Donor registry is recommending that transplant centers consider cryopreserving all donations. This allows you to make your donation before a patient begins their time-sensitive preparation regimen. It helps transplant centers avoid any issues that could occur if you are unable to donate on the prearranged date.

What happens if I get sick during travel for donation?

DKMS will cover the costs for your assessment, testing, and/or treatment of your illness if you acquire COVID-19 or any other infection as a result of travel for donation.

Does bone marrow or blood stem cell donation compromise my immune system?

You may be wondering, "Will I be at increased risk of contracting an infection or having trouble fighting an infection after donation?" We do not have any evidence to show that bone marrow or stem cell donation negatively affects a donor’s immune function or makes them more prone to illness after donation. A donor’s risk of contracting COVID-19 or other infections is no greater than other adults in their age range. As always, we strongly encourage good hygiene practices as recommended by the CDC to keep you safe and free of infection.

Does Fligrastim put me at a higher risk of infections?

The national registry follows up with all donors of PBSC for adverse events, including signs and symptoms of infection. In over 35,000 donors, we have not seen an increase in infections in our donors. In transplant patients, filgrastim is actually used to increase the white blood cell count to speed engraftment and reduce the risk of infection.

There are many ways to get involved and support our mission.
You can raise awareness, join the registry, host your own [registration] event, take on a fundraising challenge, or anything in between.