Australia Antigen Detection by "Sandwich" Counterelectrophoresis

Abstract

To the Editor.— Detection of Australia antigen is performed in many clinical laboratories by counterelectrophoresis (CEP). Recently J. B. Smith described a "sandwich" counterelectrophoresis (SCEP) technique which is very sensitive for the detection of alpha-fetoprotein.¹In a pilot experiment with the use of SCEP, we found that Australia antigen in the serum of a carrier could be detected at higher dilutions than by our regular CEP method. We have used a Shandon electrophoresis unit with a cooling apparatus operated at 200 m and 60 to 80 ma thus permitting completion of a run in 30 minutes. Barbital buffer at pH 8.6 is used to make 0.6% agarose plates.²Because we have found that certain sera contain a heat labile factor, probably Clq, that can mask Australia antigen just as rheumatoid factor can, all fresh specimens are heat inactivated for 30 minutes at 56 C.³Human rather than