ADVANTAGES OF THE SCANNING ION MICROSCOPY FOR MAPPING HALOGEN CORTICOIDS IN NORMAL AND TRANSFORMED-CELLS IN CULTURE

The intra-cellular distribution of eight halogen glucocorticoids was i nvestigated by ion microscopy in two cellular varieties of cultured no n-cancer cells (fibroblast 3T3) and cancer cells (human breast tumor c ells MCF-7). Two type's of ion microscopy helped to determine this dis tribution, a direct imaging ion microscope (SMI 300) with low spatial resolution, and a scanning ion microscope (IMS4F), featuring high reso lution, serving to obtain maps representing the intra-cellular distrib ution of the fluorine elements and drugs present in these monolayer cu ltured cells. The fluorine images representative of the drugs containi ng fluorine showed that these drugs are essentially concentrated in th e cell nuclei. In these nuclei, the distribution of these drugs is dif ferent from that of heterochromatin and of the nucleolus.