Requests and Samples

Although a rare occurrence, ABO incompatible transfusions can cause patient morbidity and mortality. Up to 20% of all incompatible transfusions are traced to patient misidentification and/or sample mislabeling errors that occur before a sample arrives in the laboratory. Laboratories play a significant role in preventing incorrect transfusion by identifying wrong blood in tube and rejecting mislabelled samples. Wrong blood in tube (WBIT) events occur when a blood sample taken from a patient is labelled with a different patient’s details. To reduce the risk of WBITs leading to ABO incompatible transfusion, the RD&E operate a two-sample policy. The two samples may be an historic and a current sample, or two samples taken by different operators, or two samples by the same operator taken at different times.

At the RD&E we operate a zero tolerance approach to  request form and sample labelling for patient identification details, in accordance with the Transfusion Policy. The request form and sample MUST be labelled with the following, matching details:



Date of Birth

NHS or Hospital Number

Details on the sample MUST be handwritten unless the Haemonetics on-demand electronic sample labelling system is used (RD&E in-patients only). A pre-printed label may be used on the request form.

Any samples/request forms that do not comply with the above will be rejected and the patient will need to be re-bled.

Request forms for blood transfusion MUST confirm if the patient has any special requirements or not by ticking the relevant boxes on the form.

Samples are valid for 72 hours from collection. This may be extended to 7 days under certain circumstances and following discussion with a Consultant Haematologist or a member of the Hospital Transfusion Team.

All WBIT events are fully investigated by the Hospital Transfusion Team, in accordance with the Investigation of WBIT Procedure.

Click here to access information regarding individual blood transfusion tests:

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Antenatal Blood Group

Direct Antiglobulin test


Additional Transfusion Tests

White cell and Platelet Investigations (Histocompatibility & Immunogenetics ) are referred to the NHSBT on the advice of a Consultant Haematologist. Contact the laboratory for advice on specific request forms for these tests.