An improved method with high sensitivity and low background in detecting low β-galactosidase expression in mouse embryos

PLoS One. 2017 May 5;12(5):e0176915. doi: 10.1371/journal.pone.0176915. eCollection 2017.


LacZ is widely used as a reporter in studies of gene expression patterns. β-galactosidase, the product of LacZ gene, is usually detected by X-gal/FeCN staining. In X-gal/FeCN staining, β-galactosidase catalyzes X-gal to produce blue precipitates, which indicate the expression patterns of the gene of interest. A newer LacZ detection method using S-gal/TNBT is more sensitive but plagued by high background. Here, we describe an improved procedure that combines advantageous steps from the two methods. By comparing with X-gal/FeCN and S-gal/TNBT methods in detecting the expression patterns of miR-322/503 and miR-451 at a series of developmental stages, the improved method showed higher sensitivity and lower background. Thus, the improved method could be an alternative way of β-galactosidase staining in low gene expression situations.

MeSH terms

  • Animals
  • Embryo, Mammalian / enzymology*
  • Female
  • Lac Operon
  • Limit of Detection
  • Male
  • Mice
  • Mice, Knockout
  • Reproducibility of Results
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism*


  • beta-Galactosidase

Grant support

This work was supported by funds from the University of Houston (to YL) and American Heart Association grants 11SDG55260033 and 16GRNT27760164 (to YL).