TUNEL Apoptosis Detection Kit (FITC) TUNEL

The TUNEL (TdT-mediated dUTP Nick End Labeling) Apoptosis Detection Kit can be used to detect apoptosis (programmed cell death) in individual cells.

During apoptosis, activated endogenous endonucleases cleave genomic DNA at internucleosomal regions, generating DNA fragments of approximately 180–200 bp that appear as a characteristic DNA ladder upon electrophoretic analysis. Detection of this DNA fragmentation is a widely used marker of late-stage apoptosis. The TUNEL (TdT-mediated dUTP Nick End Labeling) Cell Apoptosis Detection Kit (FITC) is designed to detect nuclear DNA fragmentation in apoptotic cells and tissues. The assay is based on the enzymatic incorporation of FITC-12-dUTP into exposed 3′-hydroxyl (3′-OH) termini of fragmented DNA by terminal deoxynucleotidyl transferase (TdT). Labeled DNA breaks can be visualized and quantified using fluorescence microscopy or flow cytometry.

This kit has a wide range of applications and can be used to detect apoptosis in frozen or paraffin sections, as well as in cultured adherent or suspended cells. This kit employs an optimized labeling system that combines FITC-12-dUTP with unlabeled dNTPs at an optimal ratio, allowing the formation of extended fluorescent “labeled tails” at DNA break sites. This design minimizes steric hindrance, reduces fluorophore aggregation and quenching, increases the number of fluorescent labels per DNA fragment, and enhances detection sensitivity while lowering nonspecific background signals.