Surface carbohydrate epitopes of Thy-1.1 and Thy-1.2 thymocytes are distinguished by a monoclonal antibody with a specificity common to peanut agglutinin.

NIMF4-31.7 is a monoclonal IgM antibody with affinity for terminal galactose residues of membrane glycoproteins, Sepharose and agarose. It is cytotoxic for a subpopulation of murine thymocytes and peripheral lymphocytes, corresponding to the peanut agglutinin-positive population, but reacts with a majority of cells after neuraminidase treatment. It has revealed a genetic linkage between the Thy-1 locus and quantitative expression of carbohydrate determinants on the thymocyte membrane.