An isotopic antiglobulin assay employing cell monolayers

The adaptation of the antiglobulin assay to cells in tissue culture plate wells streamlines the multiple washings and requires only small amounts of serum. The sensitivity of the test is sufficient to permit use of very high dilutions of the more strongly reactive multispecific HL A antisera, although a low nonspecific absorption by every serum apparently limits the sensitivity with some monospecific sera. There also may be differences between the HL A antigens on the leukocytes and on the fibroblast lines. This rapid but precise technique for performing the indirect antiglobulin assay should be widely applicable to the study of cell surface antigens on monolayers.