ABO Forward and Reverse - Tube Method

Abstract

In the gel test, ABO forward grouping and D antigen typing are performed in the Anti-A, Anti-B, and Anti-D microtubes, which contain the specific antibody incorporated into the gel. ABO reverse grouping is performed in the Buffered Gel microtubes. Agglutinated red blood cells become trapped in the gel at various levels within the microtube, depending upon the size of the agglutinates. Free nonagglutinated red cells pass through the gel and form a button of red blood cells on the bottom of the microtube. The control microtube must be negative for the results to be valid.