The human leukocyte test system

Summary In human leukocyte cultures set up with Eagle's MEM and stimulated with Difco's PHA M, DNA synthesis and mitotic indices were analyzed by means of ³(H)-thymidine autoradiography and cell counting from 23 up to 52 h after culture initiation. Considerable amounts of DNA synthesis and mitoses were found in this time span. This resembles the results found with Ham's F-10 medium. However, the DNA synthesis pattern and the distribution of mitotic indices indicate a higher yield of asynchrony in Eagle's MEM as compared with Ham's F-10 cultures. Proportions of first, second, and third mitoses at 72 h culture time were determined with different methods.