Cytological and autoradiographic investigations of the influence of phyto-haemagglutinin on blood cell cultures

The influence of phyto-haemagglutinin (PHA) on blood cells in vitro was studied on preparations from the blood taken from the veins of healthy adults to which tritium-thymidine had been added. Observations were made on chromosomes after treatment of the cells in hypotonic solutions on the one hand and on smears of distinguishible and as far as possible undamaged cells of the population on the other. For purposes of comparison, autoradiographic evaluation of the specimens was carried out both by the stripping and by the dipping method. The tritium index obtained by counting of labelled cells was used as a measure of cell proliferation. Autoradiographic results were compared with observations of the morphological condition of the samples. In one series of experiments, the duration of the tritium-thymidine treatment was varied whilst the incubation period was kept constant at 72 hours. In a second series, incubation was terminated at different times, always seven hours after tritium-thymidine application. An attempt was made to measure the uptake of thymidine by counting the silver grains over mitoses. Results of thses investigations will be reported on in the second part of this paper in issue no 7 of G-I-T. (orig.)