Technical Note: TACS-XL in situ Apoptosis Detection Kits

apoTACS™ is designed for the in situ detection of apoptosis in tissue and cell culture samples immobilized on slides. apoTACS contains a highly sensitive antibody detection system targeting nucleotides incorporated onto the 3' OH ends of DNA fragments. DNA end labeling in the apoTACS kits is performed using terminal deoxynucleotidyl transferase (TdT) to incorporate bromodeoxyuridine triphosphate (BrdUTP).1-2 Incorporation of BrdUTP is more efficient than either biotinylated or digoxigenin-labeled nucleotides.3 The incorporated BrdU is detected using an anti-BrdU antibody conjugated to biotin, followed by a streptavidin-horseradish peroxidase conjugate and detection reagent. Methyl Green counterstain is provided with the DAB kit and Nuclear Fast Red counterstain is supplied with the TACS Blue Label kit to enhance staining results.

TACS in situ Apoptosis Detection Kits
in situ detection of apoptosis in fixed frozen, paraffin-embedded, or plastic-embedded cells and tissues

  • strong signal with very low background
  • less sensitive to protease-induced fals positive labeling than digoxigenin or biotin-based kits
  • double labeling option
  • TACS-nuclease reagents for generating sample-specific positive controls
  • options in staining and module purchases
TACS-TACS Blue Label

Figure 1. apoTACS labeling of mouse thymus tissue. Mouse thymus was fixed in 10% neutral buffered formalin, then paraffin-embedded. Five micron sections were prepared and samples were immobilized on slides. Labeling of the tissue was performed as described within the apoTACS protocol.

Complete kits contain labeling and detection reagents and TACS Nuclease reagents for generating sample-specific positive controls. The apoTACS kits offer flexibility by providing a choice of staining solution (DAB, or TACS Blue Label) and appropriate counterstaining solutions or a basic kit for laboratories already set up for immunohistochemistry. The apoTACS Replenisher kit contains a replacement of limiting reagents within the apoTACS kits.


  1. Gavrieli, Y. et al. (1992) J. Cell Biol. 119:493.
  2. Lovelace, C.I.P. et al. (1996) Biomedical Products 21:76.
  3. Li, X. and Z. Darzynkiewicz (1995) Cell Proliferation 28:571.
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