Bone marrow

Every 40 minutes someone in Australia is diagnosed with blood cancer. For some of them, a blood stem cell or bone marrow transplant is their only chance to live.

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By Mayo Clinic Staff


How Many Times Can You Donate Bone Marrow?

This is a common question and one that cannot be answered definitively. When you sign up to become a bone marrow donor, you’ll be placed on a donor registry, and you may be contacted right away. Alternatively, it could be years before you’re contacted (if ever) to make a donation.

Whether you’re called to donate depends on geographical location, blood type, and other factors.

Joining the national bone marrow registry

The registry needs donors of all races and ethnicities to provide the best matches for the most patients. They accept donors between the ages of 18 and 60. But because bone marrow transplant is most successful with younger donors, people ages 18 to 44 are preferred.

Donors must be in excellent health. Certain diseases, medications, treatments and weight limits can exclude you from becoming a donor.

For more details about medical qualifications and how to donate bone marrow, go to Be The Match.

Who’s Eligible to Donate Bone Marrow?

There are age and medical requirements you’ll need to meet to become a donor.

And these vary from place to place.


One of the biggest requirements for donors is age.

You have to be over 18 years old to donate bone marrow.

But you also can’t be older than a certain age.

The age cap varies.

For example, Gift of Life allows people up to 60 to join its registry. But it’s only free to register for those who are aged between 18 and 35, as it says transplant centers are less likely to request older donors. Donors over 36 years old will have to pay the laboratory processing fee for their swabbing kit, which costs $60.

Be The Match looks for donors aged from 18 to 44 years old, but will also allow donors up to 60 years of age to donate. Again payment is required to join for donors above 44 years old.

Basically, the required donor age ranges from 18 to 60 years old.

Do check the eligibility requirements for the registry you plan to sign up to.

The age limit for donors is not intended to discriminate.

The reason for the age cap is that cells from younger people tend to provide better outcomes to patients according to research.


Another important criteria is your weight. With most registries you have to meet a certain weight to height ratio.

So your BMI should be in a healthy range.

If your BMI, both underweight and overweight, would present a risk to your safety then you might not be eligible to register.

Many registries, like Be The Match have weight guidelines for joining so do check those out.

For most places, the height and weight guidelines allow a BMI of up to 40.

Weight limits are not intended to be discriminatory – instead they are to ensure donor safety. Donors with a higher BMI may face complications like increased risk for anesthesia when donating bone marrow, and with PBSC, compromised access to the veins.

Other Eligibility Factors

There are many other factors that determine a person’s eligibility. For example, people with HIV or AIDs are unable to donate.

Other medical issues, like asthma, some autoimmune diseases, and a history of heart surgery or heart disease may prevent you from donating bone marrow.

Most registries have a list of medical conditions that would rule a person out as a donor.

Do check with the particular registry you sign up with.

How is Bone Marrow Matched?

Getting a match can be difficult.

Doctors search for a donor that matches a patient’s tissue type – particularly the human leukocyte antigen (HLA) tissue type.

HLA is a complex of genes found in every person’s DNA that regulate your immune system.

Basically HLAs are proteins or markers that your immune system uses to recognize which cells belong in your body and which ones don’t.

Since HLAs are responsible for whether a transplant is accepted or rejected by the body a close match between your markers and the patient’s is crucial.

To match you to a patient, you will have a sample collected from inside your cheek on a cotton swab.

This will determine your tissue typing.

As HLA is a genetic factor that is inherited from parents, you might think that the patient’s family would make the best donors.

However, only around 30 percent of patients find a suitable donor within their own family. This is because the genes you inherit are a combination from your parents.

The 70% of patients that can’t find a match in their own family have to search marrow donor registries to find a match.

According to Be The Match, about 1 in 430 people on the registry in the US will actually donate bone marrow or peripheral blood stem cells (PBSC) to a patient.

There is a huge variation in tissue types, so you might not ever donate.

If your tissue is pretty common, then you may match someone.

If you have an uncommon tissue type then you might never match a patient. On the other hand, you could be the only one on the registry who could save someone’s life.

Bone marrow donation procedure

If you are a match for someone needing a transplant, you will start the process of donating bone marrow stem cells. This process is the same whether you are donating for a relative or for someone using the National Marrow Donor Program registry.

Before your donation, you will spend a couple of days undergoing a consultation that includes:

  • Thorough health evaluation
  • Medical history
  • Blood tests
  • Filling out consent forms
  • Meeting with doctors about the donation procedure

How stem cells are extracted

There are two ways to obtain the stem cells used in a bone marrow transplant. The transplant recipient’s doctor will determine which method is best for his or her condition. The two procedures are:

  • Bone marrow harvesting: Doctors use needles to withdraw liquid bone marrow from both sides of the back of your pelvic bones. This is a surgical procedure that usually takes one hour. You will receive anesthesia so that you feel no pain during the extraction. Most people go home from the hospital that same day, but some donors stay overnight for observation.
  • Apheresis: Apheresis is a nonsurgical, outpatient procedure. Instead of collecting bone marrow, it allows for collection of peripheral blood stem cells.
  • Preparation: For five days before apheresis, you will get injections of filgrastim. This drug stimulates your bone marrow to make more stem cells and release them into your bloodstream.
  • Procedure: On the day of the donation, expect to spend up to eight hours at the collection facility. A catheter (thin, flexible tube) is placed in a large vein in your arm. The blood will flow into a machine that separates the stem cells from the blood. A catheter in your other arm transfers the remaining blood back to your body.

Why Donating Bone Marrow isn’t a Good Way to Earn Cash

It’s not legal to make money selling bone marrow so it really isn’t a viable option for anyone looking to make money.

Donating bone marrow is important and more people should register to do it.

For making cash though give it a miss.

Unlike sperm donation, there’s no infrastructure or market in place that actually caters to marrow donors who want to be paid.

It’s just not available yet.

The Flynn court case we mentioned above could change all of that.

For now though, it’s not a good way to make money.

So what do we recommend instead?

Bone Marrow Donation Risks

As with any medical procedure, there are always potential risks involved. Common complications include damage to the nerve, bone, or muscle in your hip region as well as potential issues with anesthesia.

Approximately 2.4% of patients donating bone marrow experience complications.

Rest assured, you’ll be covered with a donor life, disability and medical insurance policy for any complications related to donating bone marrow.

Blood Stem Cell Procedure

The doctor will give you a medication, several days before, that causes your body to make more blood cells. They’ll use a catheter, or a small tube, to draw the blood. Then they’ll run it through a machine to take out the stem cells (apheresis) and put what’s left back into your body. This usually takes 1 to 2 hours. You’ll likely do this two to four times. The exact number depends on how many stem cells are needed.

Why it’s done

Every year, thousands of people in the U.S. are diagnosed with life-threatening diseases, such as leukemia or lymphoma, for which a stem cell transplant is the best or the only treatment. Donated blood stem cells are needed for these transplants.

You might be considering donating blood or bone marrow because someone in your family needs a stem cell transplant and doctors think you might be a match for that person. Or perhaps you want to help someone else — maybe even someone you don’t know — who’s waiting for a stem cell transplant.

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Who can join

We are looking for:

  • male blood donors who are between 17 and 40 years old
  • women who are aged between 17 and 40 and from black, Asian, minority ethnic or mixed (BAME) backgrounds

We use these criteria to target donors we are short of on the register. 

Whatdodonors saydonatingfeels like?

Is it painful? 

‘I expected the procedure to be painful and very tense and serious but I ended up basically just taking a long nap and watched a few movies. It was quite cosy especially with heated blankets to allow my blood to flow better. All in all it was quite therapeutic.

What happens next once you’ve joined

We will add your tissue type onto our confidential digital register. 

We will keep a sample of your DNA to enable more detailed testing relating to stem cell donation in the future. You can ask us to discard this sample at any time. 

Patients and potential donors are matched by comparing HLA (tissue) types. If you come up as a potential match, we will contact you to discuss the process and ask for further blood samples. 

Information about you

All information you provide to NHS Blood and Transplant is used in accordance with the General Data Protection Regulation and all other relevant privacy and data protection laws. 

Your details remain on the register until your 60th birthday. If you are no longer eligible to give blood, please let us know as you may need to be taken off the register. 

Two types of donation by registered stem cell donors

This section covers stem cell donation by donors who have registered to join Canadian Blood Services Stem Cell Registery. For information about donating cord blood, visit How cord blood donation works.

Peripheral blood stem cell (PBSC)

PBSC are collected from circulating (peripheral) blood. Since only a small number of (blood) stem cells is released into the blood stream, a cell growth stimulating drug is administered to donors prior to the donation to dramatically increase the volume of stem cells in the blood for collection and transplant.

PBSC donors receive an injection of a drug called granulocyte colony stimulating factor (G-CSF) every day for four days prior to the donation. These injections stimulate the production and release of stems cells from the bone marrow into the blood stream. Additional injection(s) may be required on the day of the donation. The stem cells are then collected using a procedure called apheresis.

Apheresis is a collection method where only the stem cells are separated and collected during donation. The remaining blood components are returned to the donor. This is a non-surgical procedure and takes approximately four-six hours. In some cases, a second donation is required the following day.

How does bone marrow donation work? 

There are two ways to give blood stem cells. For 9 out of 10 people, it’s just like a plasma donation, but in a hospital. For the rest it’s a short surgical procedure, which requires general anaesthesia, to take bone marrow from the back of your hip.

The patient’s doctor will request their preferred method, but it’s up to you and your doctor to make the final decision.

No matter how you do it, you’ll feel incredibly special knowing you’ve helped save someone’s life. 



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