Flow Cytometry

Introduction

All of the cells within the human body have specific physical properties such as size, complexity and surface markers. By analysing cells in the body to determine which markers are present, it is possible to distinguish different cell types from one another, even if under the microscope, they may look very similar.

A flow cytometer is used to do this, which with the help of special reagents and dedicated software can provide essential information on the type of cells present in a patient’s sample.

Although the physical properties of almost any cell in the body can be analysed by flow cytometry, we are primarily concerned with the blood cells found in the peripheral blood and the bone marrow.

In the flow cytometry laboratory, we can help with leukaemia and lymphoma diagnosis, monitor disease progress in patients with human immunodeficiency virus (HIV) and test for a cell marker involved in certain connective tissue disorders such as ankyloding spondylitis.

Laboratory opening times

Monday to Thursday 9am to  5.30pm
Friday 9am to 2pm
Saturday and Sunday Closed

Tests performed in the flow cytometry laboratory

Cell markers

This test is only used when a patient has been diagnosed with a proliferative disease of the bone marrow, which is a suspected leukaemia or lymphoma. We use different test panels to differentiate between types of leukaemia and lymphoma one is chosen depending on cell morphology, clinical details and the results of other tests. This test is only generated by a haematology specialist registrar or consultant.

Sample requirements
At least 1ml of fresh whole blood or bone marrow aspirate collected into a vacutainer containing potassium EDTA. Samples should be labelled with patient’s name, hospital number and/or date of birth. The sample can be kept at room temperature (avoiding direct sunlight, radiators etc) for up to 24 hours before being processed.

Turnaround times
In cases where acute leukaemia is suspected, we aim to have results available to the haematology consultant within 2-4 hours of receiving the sample. For chronic leukaemias of lymphoid origin, results will be available within 24 hours of receiving the sample.


Lymphocyte sub-sets

This test is used to determine the health of a patient’s immune system where immunodeficiency is suspected. White blood cells, which form part of the immune system are analysed to determine which kinds are present and in what quantity. Experienced clinicians can use this information to determine whether a patient is immunodeficient and decide on what action to take to treat them.

Sample requirements
At least 0.5ml of fresh whole blood collected into a vacutainer containing potassium EDTA. Samples should be labelled with patient’s name, hospital number and/or date of birth. The sample can be kept at room temperature (avoiding direct sunlight, radiators etc) for up to 24 hours before being processed.

Turnaround times
Results can be expected to be available 24 – 48 hours from the sample being taken.


CD4/CD8 count

This test is performed on patients who have been diagnosed with HIV to monitor the progress of their disease or their response to treatment.

Sample requirements
At least 0.5ml of fresh whole blood collected into a vacutainer containing potassium EDTA. Samples should be labelled with patient’s name or soundex code (for enhanced confidentiality purposes), hospital number and/or date of birth. The sample can be kept at room temperature (avoiding direct sunlight, radiators etc) for up to 24 hours before being processed.

Turnaround times
Results can be expected to be available 24-48 hours from the sample being taken.

This test is used for disease monitoring purposes only and should not be used as a diagnostic test for HIV.


HLA-B27 antigen

Sample requirements
At least 0.5ml of fresh whole blood collected into a vacutainer containing potassium EDTA. Samples should be labelled with patient’s name, hospital number and/or date of birth. The sample can be kept at room temperature (avoiding direct sunlight, radiators etc) for up to 24 hours before being processed.

Turnaround times
Results can be expected 24-48 hours from receipt into the laboratory.