Testing the mutagenic potency of chemical substances in a linear host-mediated assay. I. Experimental microbiological...

By the use of the mutagenic substance hydrazine sulphate it is shown that the currently used single determination method for determining point mutations in host-mediated assays with calculation of mutation frequencies can lead to erroneous results. The microbiological basis for a linear-method is presented in which the population growth of the auxotrophic and substance-induced mutants used int he test can be described mathematically during their logarithmic growth phase with regression lines.