Brand:Sigma-Aldrich
Tunel Assay. Non-isotopic kit for the detection of apoptosis at the individual cell level. Apoptotic morphology is easily detected. This kit allows the recognition of apoptotic nuclei in paraffin-embedded tissue sections, tissue cryosections, or in cell preparations fixed on slide by Fragment End Labeling (FragEL) of DNA. Terminal deoxynucleotidyl transferase (TdT) binds to exposed ends of DNA fragments generated in response to apoptotic signals and catalyzes the template-dependent addition of biotin-labeled and unlabeled deoxynucleotides. Biotinylated nucleotides are detected using streptavidin-horseradish peroxidase (HRP) conjugate. Diaminobenzidine reacts with the labeled sample to generate an insoluble colored product at the site of DNA fragmentation. Counterstaining with methyl green aids in the morphological evaluation and characterization of normal and apoptotic cells.