TUNEL Based Kits
DNA fragmentation occurs as one of the final stages of programmed cell death and has long been considered a hallmark of apoptosis as well as one of the defining biochemical events of the pathway. DNA fragmentation can be detected in situ within the nuclei of fixed cells and tissues where the integrity of the DNA and the free 3’ hydroxyl groups at the sites of cleavage have been preserved by fixation.
The DNA provides a target for terminal deoxynucleotidyl transferase (TdT), which can sequentially add nucleotides to the 3’ end at the break. The addition of a nucleotide tagged with biotin (biotin-dNTP) or BrdU in the reaction mix then allows indirect visualization of any DNA labeling by TdT. Trevigen has developed a series of TUNEL-based assay kits for the in situ detection of apoptosis with colorimetric and fluorometric options. The biotin-dNTP based TACS® kits and BrdU based TACS•XL® and DermaTACS™ are tailored for the detection of DNA fragmentation associated with apoptosis in a variety of cell and tissue types and for analysis by different formats that include microscopy, flow cytometry, and 96 well plates.
TACS® Specialty Kits (15)Explore All
Trevigen has developed a series of TUNEL-based assay kits for the in situ detection of apoptosis with colorimetric and fluorometric options.
The TACS® 2 TdT Blue Label, TACS® 2 TdT DAB and TACS® 2 TdT Fluorescein kits offer Trevigen’s unique cation optimization system to enhance labeling within particular tissues. The TACS® 2 TdT Kits also employ a proprietary labeling buffer that contains no toxic components (e.g. sodium cacodylate). A highly purified form of the TdT enzyme is included for the enzymatic incorporation of biotinylated nucleotides. Biotin labeling is detected using streptavidin-horseradish peroxidase, and colorimetric substrates diaminobenzidine (DAB), or TACS Blue Label™. For fluorescent detection, a fluorescein conjugate of streptavidin is used and visualized by epifluorescence microscopy.
The TACS® specialty kits are tailored for the detection of DNA fragmentation associated with apoptosis in a variety of cell and tissue types and for analysis by different methods that include microscopy, flow cytometry, and 96 well plates. CardioTACS™, NeuroTACS™ II, TumorTACS™, VasoTACS™ have been rigorously qualified and field tested for tissue-specific labeling. These kits incorporates all the benefits of the TACS® 2 TdT kit with a tissue tailored cation system that enhances signal-to-noise ratio. FlowTACS™ is a flow cytometry variant of TUNEL and TiterTACS™ offers a 96 well plate version of the assay.
TACS•XL® In Situ Apoptosis Detection (8)Explore All
The TACS•XL® Kit is based on incorporation of bromodeoxyuridine (BrdU) at the 3’ OH ends of the DNA fragments that are formed during apoptosis. The incorporation of BrdU by TdT is more efficient than either biotinylated or digoxigenin labeled nucleotides used in other terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-based assays. The detection system utilizes a biotin conjugated anti-BrdU antibody and streptavidin-horseradish peroxidase. The combination of antibody specificity with the signal enhancing properties of biotin streptavidin results in precise cellular labeling and the highest signal-to-noise ratio observed in competitive testing.
Three general kit formats are available: TACS•XL® DAB, TACS•XL® Blue Label, and TACS•XL® Basic as well as a DermaTACS™ tailored for detection of apoptosis in skin or epithelium samples. The TACS•XL® DAB Kit is supplied with DAB and Methyl Green counterstain, and the TACS•XL® Blue Label Kit is provided with TACS Blue Label™ and Nuclear Fast Red counterstain. These complete kits provide all the reagents required for labeling including two permeabilization reagents, labeling and detection reagents, stop buffers, counterstain and TACS-Nuclease™ reagents for generating positive controls with your own samples. The TACS•XL® Basic Kit provides the reagents necessary for routine labeling, and is ideal for researchers whose labs are equipped for standard immunohistochemical procedures involving horseradish-peroxidase.