LacZ Knockin Mice

LacZ is inserted at the translational start site (ATG) or fused to the C-terminus of the target gene, typically replacing the stop codon. The LacZ coding sequence is inserted in-frame to create a fusion protein. Alternatively, LacZ can be inserted after an internal ribosome entry site (IRES) for bicistronic expression.

LacZ provides excellent sensitivity for detecting rare expressing cells through enzymatic amplification. It works in fixed tissue, enabling detailed histological analysis. Whole-mount staining enables expression mapping in embryos and organs. LacZ does not require specialized imaging equipment (microscopes with fluorescence).

Yes. LacZ reporters are frequently used to characterize Cre driver expression patterns. Crossing Cre drivers with Cre-dependent LacZ reporter lines (Rosa26-LacZ with LoxP-stop-LoxP) reveals where recombination occurs. Whole-mount or section staining shows the spatial pattern of Cre activity.

LacZ expression is detected using X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside) staining, which produces a blue precipitate in expressing cells. Staining can be performed on whole-mount specimens (embryos, organs) or tissue sections. The enzymatic reaction provides high sensitivity and permanent histological record.