Complications in the simplest cellular enzyme assay: lysis of Escherichia coli for the assay of beta-galactosidase.

Abstract A procedure for the lysis of bacterial cells for the subsequent measurement of β-galactosidase is presented. It is more reliable, reproducible, and yields higher values of enzymatic activity than do some of the techniques espoused in the literature. It is a simple technique based on detergent breakage of the cell envelope, and many samples may conveniently be processed simultaneously. Potential enzymatic inhibition by components of the lysing mixture is prevented by sufficient dilution of the lysate. A correction curve is presented for those cases where sufficient dilution cannot be made.