A quantitative spectrophotometric method to measure plant lectin-induced cell agglutination.

Abstract

A quantitative spectrophotometric method capable of ascertaining the rate and extent of cell agglutination resulting from the interaction of surface receptors and plant lectins has been developed. The technique measures both the rate of change in absorbance at 546 nm of suspensions of single cells which results from lectin-induced agglutination and sedimentation of cellular aggregates and a characteristic lag period preceding agglutination under carefully regulated conditions. These parameters were both influenced by: ( a ) the extent of lectin binding; ( b ) the initial concentration of single cells and the size of the various aggregates formed; and ( c ) enzymatic proteolysis and the presence of haptenic monosaccharides. The spectrophotometric assay was found to be capable of detecting surface differences between the plasma membranes of Sarcoma 180 and its 6-thiopurine-resistant variant, Sarcoma 180/TG.