A stability study on Gc subtyping in bloodstains: comparison by two different techniques.

The limits of determination of Gc subtypes in bloodstains were compared between the immunofixation method and the sulfosalicylic acid precipitation method using isoelectric focusing on polyacrylamide gel. By the immunofixation method Gc subtyping in bloodstains was successfully made at 37 degrees C after 7 weeks, at room temperature after 17 weeks and at 4 degrees C even after 25 weeks storage. By the sulfosalicylic method Gc subtypes were no longer able to be determined a few weeks after stain formation. The superiority of the results obtained by the immunofixation method makes it the recommended method for the Gc subtyping from bloodstains in medicolegal practice.