Colony Lift Colorimetric Assay for beta-Galactosidase Activity

UMMS Affiliation

Program in Systems Biology; Program in Molecular Medicine; UMass Metabolic Network

Publication Date


Document Type



Genetics and Genomics | Laboratory and Basic Science Research | Molecular Biology | Systems Biology


In this protocol, we present a qualitative assay for monitoring the level of expression of beta-galactosidase, an enzyme encoded by the LacZ gene, in yeast. This is useful both for determining autoactivity of LacZ expression in yeast DNA "bait" strains and for assessing LacZ reporter gene activation mediated by a transcription factor "prey" interaction with a DNA bait of interest in yeast one-hybrid (Y1H) assays. In this colorimetric assay, yeast are lysed in liquid nitrogen and then assayed for beta-galactosidase expression using the colorless compound X-gal, which turns blue in the presence of this enzyme.

DOI of Published Version



Cold Spring Harb Protoc. 2016 Dec 1;2016(12):pdb.prot088963. doi: 10.1101/pdb.prot088963 Link to article on publisher's site

Journal/Book/Conference Title

Cold Spring Harbor protocols

Related Resources

Link to Article in PubMed

PubMed ID