Private White Blood Cell Count & Blood Differential Test

A blood test to analyse the immune system looking at the white blood cell count.

Collecting blood sample 1720228532.jpg

What is a differential test?

A differential test is a white blood cell analysis to diagnose an illness affecting the immune system.

This test has a number of different uses for diagnostics which includes:

  • A differential test helps to assess your body's ability to respond to and fight infection.
  • A differential test determines the severity of allergic reactions and reactions to medications.
  • The differential test plays an important role in assessing your body's reactions to infections and chemotherapy.
  • The test can also help to identify leukaemia stages.


Need to know

Your consultant will take a blood sample from your arm. They will then take a drop of blood from your sample and smear it onto a glass slide. The smear is stained with a special dye, which helps tell the difference between various types of white blood cells.

Five types of white blood cells normally appear in the blood. These are called:

  • neutrophils
  • lymphocytes
  • monocytes
  • eosinophils
  • basophils.

A device counts the number of each type of cell in the sample. The test shows if the number of cells are in proportion with each other, and if there is more or less of one cell type.

Wear a loose fitting shirt or, ideally, a shirt with short sleeves so your arm is easily accessible for the blood test.

You may need to avoid eating and/or drinking for up to 12 hours prior to your blood test.

You may also need to stop certain medications. Speak to your consultant to discuss the details of how best to prepare for your test.

There is no recovery time or side-effects associated with this test. You will be able to leave the hospital immediately afterwards and resume with your normal daily routine.

You will need to have a follow-up appointment with your consultant to discuss the results.

Our locations

The Harley Street Clinic

The Harley Street Clinic

35 Weymouth Street W1G 8BJ London
London Bridge Hospital

London Bridge Hospital

27 Tooley Street SE1 2PR London
The Wellington Hospital

The Wellington Hospital

8A Wellington Place NW8 9LE London

This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.