There are two basic methods for the in vitro assay of B-galactosidase activity from yeast. They
differ mainly in the method of preparing the material for assay. Both methods are described with accompanying protocols. Method I: Assay of Crude Extracts includes: Yeast Cell Growth; Yeast Cell Harvest; B-gal assays; Bradford Assays. Method II: Permeabilized cell assay.