[Use of fluorescein isothiocyanate to label plasma membrane of lymphocytes].

The possibility of using fluoresceine isothiocyanate to label plasmatic membranes of lymphocytes was explored. Membrane labeling can be done under physiological conditions. The label interacted with the surface located membrane component, and the binding centers became saturated with the label concentration which left the membrane undamaged.

[Interaction of mitogenic lectins with lymphocyte plasma membranes].

It is shown that mitogenic stimuli from concanavalin A and phytohemagglutinin are summed up in the time. Under given experimental conditions each of the mitogens used did not induce mitogenesis when the interaction with lymphocytes continued for 14 and/or 20 hours. The results obtained are discussed from the point of view of the cell-to-cell interaction between the lymphocytes.