A METHOD FOR THE MEASUREMENT OF THE INFECTIVITY OF TRYPANOSOME SUSPENSIONS.

Abstract A method, based on serial dilution and inoculation of several dilutions into groups of test animals, for the estimation of the infectivity of trypanosome suspensions is described and discussed. The theoretical considerations important in interpreting the results of such experimentation are considered, and a simple method of computing end points and their standard errors is described. The results of an experiment are described; 10 replicate estimations of the trypanosome numbers in, and of the infectivity of, a suspension were made. It is concluded that the method for the estimation of infectivity is a valid one, the results obtained being in accordance with the theoretical model used.