Survival of Vero, myeloma and hybridoma cells during cold storage

Vero cells, SP2/O-Ag 14 myeloma cells and 4B87 hybridoma cells were stored either at refrigeration (5 degrees C) or freezing (-18 degrees C) temperatures. Cells were recovered every five days and percentages of viable cells were determined by the trypan blue exclusion staining method before the cells were incubated at 37 degrees C in a 5% CO2 atmosphere. SP2/0 cells grew after 30 days of storage at 5 degrees C. Hybridoma (4B87) cells survived 20 days of cold storage in HY medium and maintained antibody production. For each cell type, higher percentages of viable cells were observed among cells stored in HY medium than among cells stored in DMEM. Vero cells stored for 40 days at 5 degrees C grew when removed to optimal conditions of 37 degrees C and 5% CO2. There was no growth of cells recovered after storage at -18 degrees C.