Abstract
The present investigation deals with the cytotoxic effect of cytotoxin produced in the mouse ascites which was previously inoculated with the Yoshida sarcoma subline C cells, upon living tumor cells.
The supernatant of the mouse ascites (ARF solution) obtained on the 7th day after inoculation of tumor cells of tho Yoshida sarcoma subline C contains a certain cytooxin. That cytotoxin acts strongly upon the tumor cells in vitro as characterized by cellular damage after they displayed an amoeboid movement.
The cytotoxic activity of the cytotoxin increases remarkably after the addition of normal rat serum as a complement. The activity of the cytotoxin is neutralized by heating to 56°C for 30 minutes, but it again recovers with the addition of the complement.
The normal serum used as a complement has a little effect on the tumor cells, but enhances the cytotoxic activity of the ARF solution.
