Examination of the effects of cryoprotectants and temperature changes on cell viability in freezing different types of cells obtained from cattle and sheep

Storage of biodegradable cells in a frozen way in biobanks gives opportunities to reversibility during scientific researches or bring the missing species back by using these cells in cloning. However, freezing process can be fatal for cells therefore, during the freezing and dissolution, it is added various chemicals which is named "cryoprotectants" to the freezing solution to avoid damage against cells. In addition, freezing speed is another factor which affects the cell viability after the solution. The purpose of this thesis is the investigation of the effects of cryoprotectants and temperature changes on cell viability, storage of cells without damage and the determination (in a base of cell type) of harmless conditions to protect their viabilities in highest level during process. In this process, it was worked with two different cell lines which is obtained with primer culture from cattle and sheep. These cells are the cartilage cells from cattle and sheep's' ear and the granulosa cells that are obtained from its ovaries. Slow freezing technique, the different dose of DMSO and glycerol (%5-10) which is chosen as cryoprotectant is tried. Different doses of cryoprotectants used during freezing, the materials in which the ice cream tubes are (Mr. Frosty, Cardboard Box, Foam Box), effects of heat changes occurring during storage on cell viability and proliferation are evaluated with low cytometry and MTT analysis. As a result, the vitality ratio applied DMSO in experimental groups is found higher than the groups that is applied glycerol. It is detected that the vitality ratio of the cells which is frozen by applying DMSO in carton or foam in box is higher which is similar to cells that frozen by the applying glycerol. It is also seen that the vitality ratio during heat change in storage time is higher as well in the groups that are applied DMSO than the groups that are used glycerol. For all that, the glycerol groups which found their cell vitality low in flow cytometry is observed that after the 24hours culturing, according to the MTT results the proliferation is higher in some experimental groups. In the light of all data, in all conditions that are examined, it is concluded that the DMSO protects the cells better from the negative effects of freezing than the glycerol. It is not seen significant differences in the viability of the cells frozen in the box, Mr. Frosty, and foam. It is concluded that the critical factor is using cryoprotectant and it's concentration on cell viability. Keywords: Cell Culture, Cryopreservation, Slow Freezing, Cryopretectants, MTT Analysis, Flow Cytometry 2019, 93 Pages