抄録
Ribonucleic acid fractions extracted from spleens of immunized mice were shown to convert non-immune spleen cells to antibody-forming cells. RNA fractions which possessed the converting activity appeared in the spleen 3 to 5 days after immunization. Sucrose density gradient separation of crude RNA revealed that most of the active materials were in the 8 to 12S fraction and not in other fractions. In methylated-albuminKieserguhr-column chromatography, the activity was also recovered in a limited molecular size range. Specific activity of the RNA fractions was increased by purification procedures.
