Alternative names, keywords


Samples required

EDTA blood for group and screen (G&S) (pink cap, 6 mL tube)

For paediatrics, 2 mL EDTA is required if over 4 months old, 500 µL EDTA if under 4 months old.

Test indications


Test information

If possible requests for crossmatching for elective surgery should be submitted to the laboratory by 15:00 the previous working day. For patients with atypical red cell antibodies or other special requirements as much notice as possible is required.

Specimens are held for 7 days.

Specific rules govern the timing of specimens for crossmatch in patients who have previously been transfused:

Patients transfused or pregnant in the last 3 months:

Samples to be taken not more than 72 hours before transfusion.

Patients NOT transfused and NOT pregnant in the last
3 months:

Samples to be taken not more than 7 days before transfusion.

It is recognised that for some individuals e.g. thalassaemic patients, who have been repeatedly transfused over several years and who have not developed an antibody a more tolerant approach may be taken.
(from section 4.6 in Guidelines for Compatibility Procedures in Blood Transfusion Laboratories, British Committee for Standards in Haematology Blood Transfusion Task Force 2004).

Turnaround time

1 working day for routine requests.


Haematology (Transfusion)