Automated determination of beta-galactosidase specific activity.

We describe a modification of an automated kinetic assay for beta-galactosidase (beta-gal) activity. This modification includes an assay to quantitate the amount of protein added to each assay. The determination of specific activity includes the amount of protein in the calculation which produces a specific activity with units of pmol product produced/minute/mg protein. In addition to this modification, we present a series of macros written in Microsoft Excel for either the Macintosh or Windows on the PC. These macros decrease the amount of time required to analyze the data from beta-gal assays.