An exploratory study on the characterization of A1 and A2 bloodstains using a fluorescence immunoassay

A fluorescence immunoassay method is used in the differentiation of A1 and A2 bloodstains. Anti-A antiserum is first absorbed onto the stain. The IgM content in the eluate is then quantified by commerical Immuno-Fluor kits. The binding difference of A1 and A2 cells is retained in stains. This difference and the quantitative evaluation method provide a potential basis for blood typing or subtyping application.