[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. Modification of the membrane surface resulting from fluoresceine isothiocyanate treatment influenced significantly intercellular interactions mediating mitogen-induced blast transformation.