Glycophorin A Test

Glycophorin-A is a transmembrane protein present on the outer surface of normal human erythrocytes. In a normal erythrocyte, glycophorin-A is expressed through all stages of differentiation, from the normoblast stage to the mature erythrocyte. Once it is expressed to the maximum, the amount of glycophorin A in each red blood cell stays constant. Glycophorin A has also is also found in the blast cells of erythroleukemia cases.

The specimen with blood stain is required in this case. The specimen can be prepared in the following way: It is formalin-fixed and paraffin-embedded. The block or slide is protected from exposure to excess heat. The specimen is maintained at room temperature or is refrigerated, but it is never frozen.

Glycophorin-A test is considered as an alternative to human haemoglobin test for the confirmation of bloodstain diagnoses. It is an important test in criminal investigations.

The primary method used here is immunohistochemistry test, which is carried out in four steps as follows: Fixation: it is done to keep both tissue architecture and cell morphology intact. Antigen retrieval: it is done to raise the availability of protein for detection. Blocking: it is done to reduce the unnecessary background signals. Antibody labelling: it is done to visualise the labelled antibodies and interpret the results.