Vero 및 E6세포를 사용한 Poliovirus type 1 (Sabin)의 플라크 형성에 관한 연구 = A Study on the Plaque Formation by Poliovirus Type 1 (Sabin) in Vero and E 6 Cell Cultures

다국어 초록 (Multilingual Abstract)

In this study, a series of experiments were conducted to attain qualitative and quantitative improvements of plaque formation by poliovirus in the cultures of established cell lines. Efficiencies of plaque formation by plaque-purified poliovirus type 1(Sabin) in Vero and E6 cell cultures were assessed with regard to 1) comparison of plaque assay under direct overlay and double overlay method, 2) relative susceptibility of Vero and E6 cells for plaque formation and 3) the effects on the plaque formation of the usage of aged cell culture, of the size of cell inoculum at the initiation of cell culture, and of the substitution of either Ionagar or Agarose for Noble agar in the agar overlay medium. The results are summarized as follows;
1) Application of double overlay method resulted in a significant improvement both in the quality and quantity of poliovirus plaque formation in Vero and 56 cell cultures. Such beneficial effects of the use of double overlay method were more apparent in Vero tell cultures.
2) It was found that E6 cell cultures were much more sensitive to plaque formation by poliovirus than Vero cell cultures. The poliovirus plaques produced in 56 cell cultures were larger, smoother in the contour and more homogeneous in size than those in Vero cells.
3) R6 cell cultures could be used for plaque assay up to 20 days of incubation at 35"C after the initiation of cell culture. The aging of such cultures did not influence much on the applicability of cell cultures for plaque assay, though the younger culture appeared to be more or less superior in plaque formation to the aged cultures.
4) Cell cultures initiated with inocula of rather increased numbers of cells and grown for 4 days appeared to be quite resistant to nonspecific degeneration observed in such young cultures of Vero cells under direct overlay medium containing neutral red, and these cell cultures were feasible for plaque assay under direct and double overlay method.
5) The substitution of either lonagar or Agarose for Noble agar of the agar overlay medium did not seriously affect poliovirus plaque formations both in Vero and E6 cell cultures. Furthermore, the use of Agarose instead of Noble agar in the overlay medium Save a favorable plaque formation in these cell cultures, particularly under double overlay method.