DIFFERENTIATION OF MOUSE EMBRYONAL CARCINOMA-CELLS PCC4 BY HEAT-SHOCKAND THE KINETICS OF INDUCTION OF HEAT-SHOCK PROTEINS

Heat shock to embryonal carcinoma cells PCC4 at 45 degrees C for 30 mi n resulted in the differentiation of cells although heat shock respons e was induced on exposure to 42 degrees C for 60 min. Differentiated c ells were large and well spread with reduced nuclear/cytoplasmic ratio s as compared to undifferentiated cells. Change in cell morphology was associated with the disappearance and appearance of stage specific em bryonic antigens 1 and 3 respectively. We also found a change in intra cellular pH in PCC4 cells within 30 min of heat shock as measured by t he change in fluorescence intensity of a probe incorporated into cells during heat shock.