Use Pgal agarose minimal plate to screen lac constitutive mutation

The lacI gene has been used as a target gene in various mutation assays in bacteria and transgenic organisms. Pgal minimal plate is commonly used to select lac constitutive mutation. To simplify the preparation of the Pgal minimal plate, the agarose (1%) was used to replace agar (1.5%) in the Pgal minimal plate, omitting the process of spreading the lac(-) bacteria on the plate for scavenging the alternative carbon sources from the plate in advance of use. The results showed that the reducing sugar in agarose was extremely lower than that of others, the selective sensitivity and efficiency of the Pgal agarose was higher than those of the Pgal agar and Pgal agar scavenged. This might give the conclusion that Pgal agarose could be used conveniently and efficiently for the screening of lac constitutive mutation.