A quantitative assay for measuring cell agglutination: Agglutination of sea urchin embryo and mouse teratoma cells by concanavalin A

Abstract

Plant agglutinins are being widely used to obtain important information about cell surfaces of normal and malignant cells. In the past, agglutination has been measured using a serological estimate of cell clumping and these results suffered from a severe lack of quantification. It is important to be able to quantify the agglutination assay so that it may be used to rapidly quantify differences in cell agglutinability and correlate this with the nature and distribution of agglutinin receptor sites. In the present studies we combine the use of an electronic particle counter, a gyratory shaker with a large diameter of rotation and small volumes of cell suspensions to develop a rapid quantitative assay to measure cell agglutination with plant agglutinins. The parameters influencing agglutination are carefully studied and the results indicate that initial cell density, agglutinin concentration and temperature affect the kinetics of cell agglutination. It is suggested that some previous work be re-evaluated in light of these results. The agglutination of mouse teratoma cells and sea urchin embryo cells by concanavalin A (ConA) are also studied and carefully compared using the new assay. Teratoma cells and normal EDTA dissociated, untrypsinized, sea urchin embryo cells are agglutinated by ConA. We quantitatively show that under the same conditions equal numbers of teratoma cells and sea urchin gastrula cells agglutinate with ConA and these results are interpreted in terms of clustering of cell surface agglutinin receptor sites.