QUANTITATIVE FEATURES OF A SANDWICH RADIOIMMUNOLABELING TECHNIQUE FOR LYMPHOCYTE SURFACE RECEPTORS

Abstract

The present study was designed to devise and characterize an indirect or sandwich radioimmunolabeling technique for the study of lymphocyte surface receptors of immunoglobulin nature. Mouse lymphocytes from various sources were treated by the method of Shortman et al. to remove debris and damaged cells. This was an important preliminary step, as without it, little meaning could be attached to bulk scintillation counting of labeled cell suspensions, in view of the marked tendency of dead or damaged cells to adsorb protein nonspecifically. Next, cells were reacted at 0°C for 30 min with graded dilutions of unlabeled rabbit antisera against defined mouse Ig chains. After washing, the cells were reacted with a sheep anti-rabbit globulin reagent labeled with ¹²⁵I, again at graded concentrations. After further washing, lymphocyte labeling was quantitated by both bulk scintillation counting and radioautography.