Collecting stem cells for acute lymphoblastic leukaemia (ALL)

You might have a stem cell or bone marrow transplant as part of your treatment for acute lymphoblastic leukaemia (ALL). Part of this process is collecting stem cells from the bloodstream or the bone marrow Open a glossary item.

Stem cells are made in the bone marrow and develop into red blood cells Open a glossary item, white blood cells Open a glossary item and platelets Open a glossary item.

In ALL, stem cells are usually collected from someone else (a donor). This is called an allogeneic transplant.

Collecting your donor's stem cells from the blood

This is called a peripheral blood stem cell collection or harvest. It is the most common way of collecting stem cells for a transplant.

Preparing for the stem cell collection

First, your donor has injections of a growth factor called G-CSF. They have the injections once a day for about 4 to 7 days.

Growth factors are natural proteins that help the bone marrow to make blood cells. They make the bone marrow produce more stem cells so they spill out into the bloodstream.

Your donor has a blood test the day after the last injection to make sure they have enough stem cells in their blood. They can then have the stem cell collection.

On collection day

Your donor might have their stem cells collected over 1 or 2 days. It takes about 2 to 4 hours each time.

They lay down on a couch. The nurse puts a drip into each of their arms and attaches the drip to a machine. The blood passes out of one drip, through the machine, and back into their body through the other drip. The machine filters the stem cells out of their blood and collects them in a bag. This is known as apheresis.

You usually have the stem cells later the same day or the next day.

Side effects of a stem cell collection

During the stem cell collection your donor might have:

  • numbness and tingling around their mouth, hands or feet
  • muscle twitching
  • tummy (abdominal) cramps
  • feeling trembly or shaky

This happens if their calcium level gets low. To relieve these symptoms the nurse slows the stem collection down, they usually also take calcium supplements. Some people have calcium through a drip to prevent severe symptoms such as a seizure (fit).

Your donor usually has their calcium levels checked before each stem cell collection.

Collecting stem cells from your donor's bone marrow

Collecting bone marrow is called a bone marrow harvest.

What happens

Your donor has a general anaesthetic Open a glossary item. This means they are in a deep sleep during the procedure.

The doctor puts a needle through their skin into the back of the hip bone. They pull the liquid bone marrow out through the needle into a syringe. They then inject it into a bag.

To get enough marrow the doctor usually puts the needle into several different parts of the hip bone. Occasionally, doctors use the breast bone (sternum) as well. The doctor removes about a litre (nearly 2 pints) of bone marrow. Your donor’s body replaces these cells within a few weeks.


When they wake up, they may have up to 6 puncture sites covered with dressings. They will feel very bruised and sore. This can last for up to a week, but painkillers can help.

They usually stay in hospital overnight after a bone marrow harvest. This is to make sure they have recovered from the anaesthetic. They might also need a blood transfusion afterwards. 

Collecting your own stem cells or bone marrow

You might have a transplant using your own stem cells. This is called an autologous transplant or an autograft. But this is very rare for ALL.

You have the stem cell collection in a similar way as above.

Last reviewed: 
19 Jul 2021
Next review due: 
19 Jul 2024
  • The European Blood and Marrow Transplantation Textbook for Nurses
    M Kenyon and A Babic
    Springer Open, 2018

  • FACT-JACIE International Standards for Hematopoietic Cellular Therapy: Product Collection, Processing and Administration (7th Edition)
    European Society for Blood and Marrow Transplantation (EBMT), 2018

  • The EBMT Handbook. Hematopoietic Stem Cell Transplantation and Cellular Therapies
    E Carreras and others
    Springer Open, 2019

  • Hoffbrand's Essential Haematology (8th Edition)
    A V Hoffbrand and P Steensma
    Wiley Blackwell, 2019

  • BMJ Best Practice Acute lymphocytic leukaemia
    BMJ Publishing Group Ltd, March 2021

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.