Invitrogen™ CellEvent™ Senescence Green Flow Cytometry Assay Kit

Description

• The kit contains an optimized buffer and a fluorescein-based reagent that contains two galactoside moieties, making it a specific target for β-galactosidase
• Activation of β-galactosidase is commonly used as a biomarker for senescent cells
• This hydrolase enzyme resides in lysosomes and converts β-galactosides into monosaccharides under acidic pH conditions
• The enzyme-cleaved product is retained within the cell due to covalent binding of intracellular proteins and emits a fluorogenic signal that has absorption/emission maxima of 490/514 nm
• CellEvent Senescence Green Flow Cytometry Assay Kit features include: • Fluorescent detection of β-galactosidase hydrolysis by flow cytometry • Fixed cell assay • Multi-color compatibility When normal cells reach the end of their limited replicative lifespan, commonly referred to as the Hayflick limit, they enter into a senescent phase where they remain metabolically active without undergoing cell death processes
• These senescent cells adopt a specific phenotypic state that includes the appearance of multi-nucleated cells, increased vacuolization, expression of pH-dependent β-galactosidase, and morphological changes where cells become enlarged and extended
• Through a variety of mechanisms, they may play a role in tumor suppression, tumor progression, aging, and tissue repair
• β-galactosidase resides in lysosomes and converts β-galactosides into monosaccharides under acidic pH conditions
• The activity is optimal under lysosomal pH 4, but conventional assays measure at pH 6
• It has been shown that normalized β-galactosidase activity is twice as high in senescent cells as in presenescent cells regardless of the pH value used for testing
• Traditionally, the colorimetric substrate for β-galactosidase, 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (x-gal), has long been used to detect metabolic activity in cells in vitro
• Upon hydrolysis by β-galactosidase, x-gal converts to a blue precipitate, which is not suitable for flow cytometric assays
• Therefore, we have developed a sensitive, fluorescent substrate for β-galactosidase that can be used in flow cytometry assays for the detection of senescent cells.