The intrasanguineous host-mediated assay procedure distribution and retention of yeast in the mouse.

A study of the factors that could affect a method to detect mutations in cells recovered from different organs after intravenous injection in mice, was performed by using the D4 strain of Saccharomyces cerevisiae. The recovery of the yeast cells 5 min to 3 days after injection in the host animal was investigated. The circulation, distribution and localization of the cells were determined, and histopathologic analysis was performed in order to detect possible interactions between the mice and the microorganisms. We found that the yeast cells were trapped primarily in the capillaries of the organs; 3 days after injection no cells were found outside of the tissue-blood vessels. The spontaneous gene-conversion frequency of the yeast cells recovered at different times after injection was increased, but this increase was not time-dependent.