Cellular Senescence Activity Assay Kit uses Xite beta-D-galactopyranoside, a fluorogenic beta-Gal substrate that readily enters into live cells, and gets cleaved by SA-beta-gal inside cells, generating strong green fluorescence. Unlike cell-impermeable X-Gal substrate, it has excellent cell permeability. The Cellular Senescence Activity Assay Kit enables users to detect the senescence with higher sensitivity with robust performance.