Factors Influencing the Infectivity of Poliovirus Ribonucleic Acid. ∗

Summary

Evidence presented shows that the influence of salt concentration of the environment on RNA infectivity for mammalian cells is due at least in part to alteration of the state of susceptibility of the host cell. The 3 different cell lines tested simultaneously responded differently when exposed to the same RNA preparation diluted in varying salt concentrations. Other factors which alter host cell susceptibility, sucrose concentration, age of host cell, nutritional environment of host cell and temperature during the adsorption interval, emphasize the importance of the physiological state of the cell at time of exposure to RNA to the degree of infectivity expressed.