Stem Cell Collection

Before you can undergo a blood or marrow transplant, stem cells must first be collected from your body or from a donor.

How are stem cells collected?

The stem cell collection process varies depending on where the cells are being taken from. Stem cells can be removed directly from the bone marrow or filtered from the bloodstream.

Bone marrow

Stem cells are harvested from the bone marrow in a short surgical procedure that takes place in an operating room. The patient or donor is given anesthesia while bone marrow is taken from the back of his or her hip bone through a needle. One to two quarts of bone marrow and blood are typically removed.

Donors and patients often recover quickly from this procedure. The risks are minimal. There is no surgical incision, only a mark where the needle was inserted through the skin. You may feel an ache or soreness in your hip or lower back, but this can be treated effectively with over-the-counter painkillers.


Stem cells are extracted from the bloodstream, or peripheral blood, in a process known as pheresis. This is the procedure most commonly used at Siteman. Pheresis is the Greek word for separation, and that is exactly what the procedure does: separate stem cells from the rest of the blood. If you’re receiving an autologous transplant, this method will likely be used to collect your stem cells.

Before a patient can undergo pheresis, he or she is given injections of a drug that prompts the stem cells to mobilize, or travel from the bone marrow to the blood. The mobilization process can cause a number of side effects, most of them mild:

  • Pain in the bones
  • Sleeplessness
  • Nausea
  • Flu-like symptoms
  • Pain at the site of the injection
  • Low-grade fever

Once the mobilization drugs have taken effect, the patient or donor is ready for pheresis. The individual is connected to a special machine through an IV placed in each arm or, when patients donate their own stem cells, a central line or catheter in the chest. Blood flows into the machine, which separates the stem cells from the bloodstream and then returns the rest of the blood to the donor or patient.

Pheresis is not painful, and patients and donors are free to sleep, read, watch TV, work, or listen to music while connected to the machine.

Most of the time, stem cell collection can be completed in a single session, sometimes lasting as long as eight hours. Patients and donors may have to return for additional sessions, but most individuals at Siteman complete the process in a single four-hour session.

Pheresis usually doesn’t cause any serious side effects or complications, and most patients tolerate it well. When side effects do occur, they often are caused by the anticoagulant medicine given as part of the process, which lowers the amount of calcium in the blood. These effects include:

  • Tingling in the face, arms, or legs
  • Numbness, especially around the lips
  • Feeling dizzy or lightheaded
  • Feeling nauseous
  • Chills

Patients are encouraged to eat or drink extra calcium before and after pheresis to mitigate these effects. You can even take antacid to increase your calcium levels.