Study on Cryo-preservation of Theileria annulata Schizont Infected Cell Line Vaccine Strain S15

The purpose of this study was to examine the potential application of Sorbitol, Sucrose and Gelatin in combination with glycerol in order to Theileria annulata infected cell line cryo-preservation. The efficiency of the freezing methods was compared by assessing the viability and plating efficiency of cells after resuscitation, dilution and equilibration in cell culture medium. As a result, the conventional cryo-preservative medium containing 5% PEG treated Bovine Serum and 10% glycerol successfully cryo-preserved cell as efficiently as the standard medium containing 80% FBS and 10% glycerol and was superior to all thirteen different experimental cryo-preservative media. A crucial result was obtained among the thirteen different serum-free media which showed that the 0.2M sorbitol+10% glycerol method yielded cells with viability of 54% and good plating efficiency results. It was concluded that the conventional method would be the best and ideal for the cryo-preservation and storage of Theileria annulata-infected cells for vaccine purposes to date.