Abstract: | A new human immunogenetic cell-surface activity associated with human chromosome 11 in the AL human-Chinese hamster ovary cell hybrid is described. Like a1, but not a2, it is present on the human erythrocyte. By mutagenesis and selection, specific, stable, variants of the AL hybrid have been prepared exhibiting various combinations of a1, a2, a3, and lactic dehydrogenase A activities. The antigens of the AL system can be demonstrated by the horseradish peroxidase system which offers a promising approach to scanning of tissue cells. |