Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Phenotype investigations as required to determine the antigens carried on a red blood cell (RBC). The “phenotype” of any blood group refers to which antigens are serologically detectable on the RBC, and usually (though not always) corresponds to the genes that the patient carries. The test procedure is based on the principle of agglutination. Normal human red cell, processing antigens, will agglutinate in the presence of antibody directed toward the antigen. Rh phenotyping tests for the C, E, c, e and K antigens.
Specimen container paediatric:
1mL K2 EDTA or 6mL K2 EDTA
Specimen container adult:
6mL K2 EDTA
1mL paediatric K2 EDTA or 4mL K2 EDTA can be used in exceptional circumstances.
Minimum volume paediatric:
1mL
Minimum volume adult:
6mL
Special requirements:
The Rh phenotype test is not available for order by the Clinical area. The test is performed by the laboratory as part of serological investigations.
Sample stability:
Short term storage: 24 hours at room temperature.
Long term storage: 7 days at 4 to 6°C
Transport requirements:
Sample should be transported to Laboratory Medicine Reception via GP courier, hospital air-tube system or hand delivered to maintain storage conditions. Samples must not be subjected to extreme hot or cold conditions prior to testing.
Add on test:
Request for add on must be discussed directly with the Transfusion laboratory.
FH: 0191 2237849
RVI: 0191 2824435
Interpretation:
The presence or absence of antigens is identified by agglutination. Agglutination occurs when the red cells are cross-linked by the binding of either IgG or IgM antibody molecules. The blood group antigens reported will show whether the patient is positive (demonstrates the antigen) or negative for the antigen type.
Factors affecting result:
Incorrect specimen type received, clotted, haemolysed, icteric or lipaemic samples. Clotted samples may interfere with instrument pipetting and must not be used. Fibrin or particulate matter, clots, bubbles or scratches on the test cassette can interfere with reaction interpretations.