In vitro and in vivo assessment of the viability of dog marrow after storage.

By JOHN A. MANNICK, HARRY L. LOCHTE, JR., E. DONNALL THOMAS AND JOSEPH W. FEBREBEE R ECENT STUDIES have indicated the usefulness of stored marrow in the repopulation of marrow spaces after lethal irradiation.’4 The viability of marrow stored for this purpose is definitively demonstrated by survival of the irradiated recipient. A satisfactory in vitro test of viability, however, is essential for studies in man since opportunities for in vivo assay in patients are necessarily limited. In this laboratory desoxyribonucleic acid ( DNA ) synthesis in vitro has been used as an index of the ability of marrow cells to proliferate, since an increase in DNA is a prerequisite for cell division. In the studies on stored samples of dog marrow reported here, the relationship between DNA synthesis in vitro and cell viability in vivo was explored. The in vivo test used has been the ability of stored autologous marrow to induce survival in lethally irradiated dogs.