The burst size distribution in the growth of bacterial viruses (bacteriophages).

Burnet (1929) invented a method for measuring the yield of virus from individual bacteria (burst size). It consists in diluting a suspension of infected2 bacteria and incubating a large number of samples from the diluted suspension. Each sample should contain on the average less than one infected bacterium. Only a small fraction of the samples will then contain more than one infected bacterium. The samples are incubated until all bacteria are lysed, and then plated. Burnet did not apply this technique on a scale sufficiently large to indicate the distribution of individual burst sizes. Ellis and Delbriick (1939) and Delbriick (1942) obtained results which indicated an exceedingly wide variation of the burst sizes. However, these series of experiments were neither sufficiently large nor sufficiently accurate to give a clear idea of the burst size distribution. With some minor improvements in technique we have now succeeded in obtaining a fair approximation of the distribution.