Biological assay for microbial contamination

摘要

A semi-quantitative method for determining the concentration of viable coliforms or E. coli in a liquid is provided. The sample to be tested is mixed with an indicator reagent which includes a specific indicator compound that undergoes a change that is detectable by spectrophotometric or visual methods upon cleavage by a beta galactosidase enzyme found in coliforms or a beta glucuronidase enzyme unique to E. coli.