Abstract
Influenza virus, treated with sodium periodate, was adsorbed well on red cells but lacked the capacity for spontaneous elution. Heated virus was eluted from red cells by the action of cholera vibrio filtrate, unheated influenza virus, and to a small extent by heating at 56°C. Periodate-treated virus was not elutable by these methods but was liberated by exposure of the adsorbing cells to concentrations of sodium chloride of 5 to 10 per cent. This treatment had no effect on elution of heated virus.