How Bone Marrow and Stem Cells are Collected

The procedure to collect stem cells that will be transplanted into a patient is called a bone marrow or peripheral blood stem cell harvest.

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If you are providing the blood stem cells for a transplant, they will either be collected from your bloodstream (peripheral blood) or from your bone marrow.

Collecting Stem Cells from the Bloodstream 

The largest concentration of blood stem cells is in your bone marrow. However, the blood stem cells can be moved or "mobilized" out of the bone marrow into the bloodstream (peripheral blood) where they can be easily collected. This is called a peripheral blood stem cell harvest.

A peripheral blood stem cell harvest is not a surgical procedure and is usually performed in an outpatient clinic.

Prior to the harvest, you will be given injections of a drug called granulocyte colony stimulating factor (G-CSF), to move stem cells out of the bone marrow into the bloodstream where they can easily be collected.

If you are collecting stem cells for your own transplant, chemotherapy drugs may be used to help move the stem cells out of your bone marrow into the bloodstream.

Caitlin Emma Stem Cell Harvest

Peripheral blood stem cell collections are done in an outpatient clinic.

  • You will sit in a comfortable chair or bed.
  • A needle connected to flexible tubing will be inserted into a vein in each of your arms.
  • Blood will be withdrawn from one arm and passed through a machine that separates out the stem cells.
  • The rest of the blood product will be returned to you through the tubing connected to the needle in your other arm.

If you have small arm veins, stem cells can be collected through special flexible tubing that is inserted into a large vein near the groin or under the collarbone. 

Depending on the number of stem cells collected during each  session, it may take one-to-five days to collect enough stem cells for transplantation.

Some donors feel lightheaded, cold or numb around the lips during  the collection. Others experience cramping in their hands caused by a blood-thinning agent used during the procedure that reduces the level of calcium in the blood. The cramping usually resolves after treatment with calcium supplements or temporarily stopping the procedure. 

Other possible short-term side effects include bone pain, headache, fatigue and nausea. Rarely, there will be bleeding at the puncture site since it takes a few hours for all of the blood thinners to clear.

Collecting Bone Marrow 

The procedure used to collect bone marrow for transplant is called a bone marrow harvest. It is a surgical procedure that takes place in a hospital operating room. Typically it is done as an outpatient procedure.

Most collections are performed with general anesthesia although sometimes it can be done with only spinal anesthesia blockade. While you are under anesthesia, a needle will be inserted into your rear hip bone where a large quantity of bone marrow is located. The bone marrow will be extracted with a syringe.

Several skin punctures on each hip and multiple bone punctures will be required to extract sufficient bone marrow. There are no  surgical incisions or stitches involved, only skin punctures where the needle was inserted which will be covered with a sterile bandage.

The amount of bone marrow harvested depends on the size of the patient and the concentration of blood stem cells in your marrow.

Typically one to two quarts of marrow and blood are harvested. While this may sound like a lot, your body can usually replace it in four weeks.

When the anesthesia wears off you may feel some discomfort at the harvest site. The pain will be similar to that associated with a hard fall on the ice and can usually be controlled with acetaminophen (Tylenol®). 

Most people can resume normal activities in a few days although activities such as climbing stairs or sitting in one place for a long period of time may be uncomfortable for a week or two. You will also be advised to avoid heavy lifting for two weeks.

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Next Page: Finding a Bone Marrow, Stem Cell or Cord Blood Donor

Updated June, 2024