The replica plating method as developed by Lederberg has been used to differentiate between "true" and "false" histidine-requiring revertant bacterial colonies which develop on minimal agar plates in the Ames test. Strains of S. typhimurium LT2, TA 100, when exposed to either sodium dichromate or the fumes from the welding of stainless steel, develop colonies whose apparent numbers are directly...

background: welding is one of the most exercised industrial processes which welders are exposed to chemical and physical hazardous agents. this study was conducted to evaluate occupational and environmental exposures to aerosols generated by welding processes in a factory. methods: a total of 28 samples of aerosols were collected at 4 different locations including indoor, outdoor, source of wel...