Vytautas Pavilanis

Freezing and storing of monkey and rabbit kidney cells for tissue cultures

Summary Cercopithecus monkey kidney cells were more table if frozen from primary cultures than those from fresh trypsinizations when dimethyl sulfoxide in medium 199 was used as the additive. No such difference could be seen with rabbit kidney cells frozen in the same conditions. Rhesus monkey cells were less viable if frozen from primary cultures than those from fresh trypsinizations when glycerol in Eagles basal medium was used as the additive. Cercopithecus monkey kidney cells showed a half-life of 5 months when stored in a mechanical freezer at −85°C. The longer the period of storing was, the less the number of cultures could be mitated and the later the confluency was reached in culture. The time during which these cells are kept in the fusion zone (0.5 to 40 min) of the freezing curve did not affect the viability of the cells.

Evaluation de l'efficacité de la technique d'adsorption-élution du poliovirus 1 sur filtres en fibres de verre: application à l'analyse virologique de 100 ml à 1000 ℓ d'eau

The efficiency of the adsorption-elution technique using fiber glass filters to concentrate viruses from water was evaluated to detect poliovirus type 1 in drinking, river, and sewage water. At pH 3.5 and with 5 × 10−4 M aluminium chloride more than 99% were adsorbed to a 0.25-μm filter. Beef extract (3%), pH 9, eluted 85–95% of the adsorbed viruses and organic flocculation at pH 3.5 permitted to reconcentrate the viruses in 1/20of the elution volume with a 50–72% efficiency. The overall efficiency of the technique for 100 ml to 1000 l of the different types of water using 102 to 106 PFU was 38 to 58%.

Some optimal conditions in freezing rabbit kidney cells for tissue cultures.

Summary Primary rabbit kidney cells were frozen in liquid nitrogen and recovered for tissue cultures. Viability was tested using dye exclusion, cell attachment and growth confluency. It was shown that cells frozen under optimal conditions were more viable when harvested from young actively growing cultures than from cultures which have reached maximum growth. Measuring cell viability by the dye exclusion test must be carefully appraised since the cell attachment assay indicated that the values of viability were high in relation to the actual capacity of the cell to attach and stretch out on the glass.