LIQUID NITROGEN PRESERVATION OF MAMMALIAN CELLS IN A CHEMICALLY DEFINED MEDIUM AND DIMETHYLSULFOXIDE

Three established mammalian cell lines cat kidney, L, and HeLa cells grown in suspension in a protein-free chemically defined medium have been preserved successfully in a liquid nitrogen refrigerator in the defined medium fortified with dimethylsulfoxide. The optimal concentration of dimethylsulfoxide for the preservation of cat kidney and L cells was 4. The optimal concentration of dimethylsulfoxide for preservation of HeLa cells was 8. Recovery of viable cat kidney and L cells after one months storage was 86 as judged by the trypan blue dye exclusion method. The thawed cells yielded normal growth upon inoculation into growth medium. The viability of Hela cells after one months storage was 86 and normal growth resulted upon reinoculation in growth medium.