For instance, in our experience with mallein 3 hours' contact between red ceils
and a certain amount of mallein was found necessary at room temperature to
cause maximum sensitization of the cells to agglutination by antimallein sara,
while at 37°C. the same effect was brought about in 10 minutes (5). In contrast,
cells treated with tannic acid immediately adsorb the protein antigens to which
they are exposed and do so as well at 0--4°C. as at higher temperatures.