Cytology of human bone marrow subjected to prolonged storage at -79 C

It was observed that human bone marrow cells preserved at -79 C with 15% glycerol exhibited marked morphological changes when examined by conventional cytological methods, and that techniques designed to remove glycerol slowly produced still more damage. By contrast, cells from which the glycerol was removed rapidly by abrupt dilution in an isotonic medium were found to be morphologically intact when examined on cellulose acetate membrane filters: the quantitative recovery was 74%, and undoubted proof of viability was provided by the demonstration of motile cells. When bone marrow was examined after storage for periods up to 3 frac12 years it was noted that a progressive loss of cells occurred, and a variety of cytological techniques, including staining by Romanowsky, Feulgen, PAS, Sudan black, and pyronin techniques and supravital staining with acridine orange and trypan blue all provided further evidence of progressive deterioration during storage at -69 to -79 C. human bone marrow preservation; human bone marrow viability; cryobiology Submitted on May 20, 1963