A statistical evaluation of the binding of ferritin-conjugated lectins to the surface of rat cells. Topographical variations as a function of lectin concentration and cell type.

Statistical procedures were utilized to evaluate the concentration dependence of labeling by ferritin-conjugated lectins on four different rat cells: hepatocytes, normal thymocytes, Friend virus-induced rat tumor cells and feline sarcoma virus-induced rat sarcoma cells. Labeling by ferritin conjugates of concanavalin A, wheat germ agglutinin and Ricinus communis agglutinins I and II was quantitated by counting the number of ferritin granules on 600 Angstrom membrane segments. Relationships between the arithmetic means and variances for sample populations from each cell and ferritin-lectin combination were used to define four types of topographical distributions: uniform/ordered, uniform/random, random and clustered. It was found that the distribution and/or density of surface-bound lectin was concentration-dependent for all four ferritin-lectins. The nature of this dependency was complex and varied with both lectin and cell type.