Association of exogenous RNA with Novikoff hepatoma ascites cells.

RNA taken up into the cells. The 4 types of RNA used included whole cellular 4 5, 18 5, and 28 S RNA from NHAC and the very GC-rich B3 fragment enzymatically cleaved from 28 S RNA of NHAC (1 7, 37, 37). The B3 fragment, composed of approximately 550 nucleotides, was chosen because it is highly hydrogen bonded and is less susceptible to degradation by RNase. The present results show that the cell-associated radioactivity of exogenous RNA mainly results from adsorption of the RNA to the cell surface rather than uptake of the RNA into the cells. It is possible that small percentages of the RNA or its products are transported into the cells.