THE INFLUENCE OF HOST RESISTANCE ON VIRUS INFECTIVITY AS EXEMPLIFIED WITH BACTERIOPHAGE

Abstract

Increasing the volume of agar in which a mixture of susceptible bacteria and coliphage are plated markedly decreases the plaque count obtained. This effect is not upon the size of the infective unit, but upon the proportion of units successful in forming plaques, as shown by dilution expts. The relationship of this finding to the statistical problems encountered in other virus titrations is discussed.