A sensitive immunoblotting procedure has been applied to the detection of alpha-2-HS-glycoprotein (A2HS) phenotypes from control and casework bloodstains. A2HS phenotypes were separated by thin layer polyacrylamide gel isoelectric focusing (PAGIEF) in gels containing Pharmalyte pH 4.2-4.9. After transfer to nitrocellulose by a rapid capillary blot, the A2HS phenotypes were developed using a double antibody enzyme-immunoassay. The evaluation of A2HS phenotyping of casework material was undertaken in parallel with phosphoglucomutase (PGM) phenotyping by PAGIEF. A total of 598 water extracts from casework bloodstains have been tested. Positive results were obtained in 84% and 75% of samples for PGM and A2HS respectively. The A2HS gene frequencies A2HS*1 = 0.6420, A2HS*2 = 0.3530, and A2HS*3 = 0.0050 were determined from a survey of 1000 people in Brisbane.