BINDING OF CONCANAVALIN-A TO LYMPHOCYTES AFTER STORAGE AT-196-DEGREES-C

A reported loss in the binding capacity to ConA of thawed human peripheral blood lymphocytes has been investigated using two methods. With acetyl-3H ConA there was an apparent loss in the total binding of ConA to 2 × 105 dye-excluding cells thawed from liquid nitrogen, after cooling with a two-step procedure of 10 min at -26 °C in 5% DMSO. Using the same cooling method, this apparent loss of binding capacity was not confirmed when a Fluorescence Activated Cell Sorter was used to measure the binding of fluorescent labelled ConA to thawed cells that are shown to be within the light scatter range of unfrozen lymphocytes. This second method, therefore, shows that a large population of lymphocytes can be recovered after thawing without any loss of receptors for ConA. The loss of binding measured by the radioactive method may be due to damaged lymphocytes and also to the loss of the small numbers of residual granulocytes. © 1979.