Tissue typing

Tissue typing is a set of tests that are done with your blood and saliva. You might have it if your doctors think that you need a ​stem cell or bone marrow transplant​  from someone else (donor transplant). It is to show how closely a possible stem cell or bone marrow donor’s tissue matches your own.

You might also hear this test called other names such as:

• HLA tissue typing

• HLA typing

• Histocompatibility testing

• HLA crossmatching

You usually have one or more of the following tests:

• a blood test

• a swab taken from the inside of your cheek (buccal swab)

• a spit (saliva) sample

Preparing for your tissue typing test

Blood and mouth swab test:

You can eat and drink normally before your test. Take your medicines as normal.

Saliva sample:

You should not eat, drink, smoke or chew gum for 30 minutes before giving this sample.

What happens?

Blood test:

You sit or lie down to have the test.

A doctor, nurse or phlebotomist (person specialised in taking blood) chooses the best vein to use. This is usually from your arm or hand. Let them know if you are afraid of needles, get unwell with the sight of blood or are allergic to plasters or latex. 

They put a tight band (tourniquet) around your arm above the area where they take the sample. You may need to clench your fist to make it easier to find a vein.

They clean your skin and then put a small needle into your vein. Next, they attach a small bottle or syringe to the needle to draw out some blood. They might fill several small bottles.

Once they have all the samples, they release the band around your arm. They then take the needle out and put pressure on the area with a cotton wool ball or small piece of gauze for a few minutes. This helps to stop bleeding and bruising.

Look away when they’re taking the blood if you prefer. Tell your doctor, nurse or phlebotomist if you feel unwell.

Mouth swab test:

The swab looks like a very long cotton bud. You or your nurse can do it. If doing it yourself it might be best to do it by looking in the mirror.

Your nurse might ask you to sit upright in a chair or if you prefer you can stand.

The nurse or you will then remove the swab from the packet. Do not allow the tip of the swab to touch anywhere else apart from the inside of your cheek. You or the nurse then rubs the swab on the inside of your cheek for several seconds. The swab is then placed into the tube to be sent to the laboratory.

Saliva sample:

You sit upright in a chair or if you prefer you can stand. You then spit the saliva into the container. This then sent on to the laboratory for testing.