TUNEL method

The TUNEL assay ( T dT-mediated d U TP-biotin n ick E nd L Abeling ) is used to represent cell nuclei of apoptotic cells . “TdT” stands for “terminal deoxynucleotidyl transferase” , an enzyme that is used in an intermediate step in the technology.

method

During apoptosis , the deoxyribonucleic acid strand (DNA strand) of the cell nucleus is fragmented by the activity of endonucleases . The hydroxyl groups (3'-OH groups) released at the break ends are provided with labeled nucleotides by the enzyme TdT , which z. B. can be made visible on the basis of fluorescence with appropriate microscopes .

The method was first described in 1992. The method was criticized in the years that followed, since a distinction between necrotic and apoptotic cell death was only possible to a limited extent. In the following years it has been described how the technology can be modified and improved with regard to problems that arise.

Web links

Jennifer Jewell, Andrea M. Mastro: Using terminal deoxynucleotidyl transferase (TdT) enzyme to detect TUNEL-positive, GFP-expressing apoptotic cells. (pdf; 62 kB). In: Cell Notes. 3, 2002, pp. 13-14.

Individual evidence

↑ Y. Gavrieli include: Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. In: J Cell Biol . 119, 1992, pp. 493-501. PMID 1400587
↑ B. Grasl-Kraupp et al .: In situ detection of fragmented DNA (TUNEL assay) fails to discriminate among apoptosis, necrosis, and autolytic cell death: a cautionary note. In: Hepatology . 21 (5), May 1995, pp. 1465-1468. PMID 7737654
↑ A. Negoescu include: Importance of DNA fragmentation in apoptosis with regard to TUNEL specificity. In: Biomed Pharmacother . 52 (6), 1998, pp. 252-258. PMID 9755824
↑ F. Labat-Moleur et al .: TUNEL apoptotic cell detection in tissue sections: critical evaluation and improvement. In: J Histochem Cytochem . 46 (3), Mar 1998, pp. 327-334. PMID 9487114
↑ A. Negoescu include: In situ apoptotic cell labeling by the TUNEL method: improvement and evaluation on cell preparations. In: J Histochem Cytochem. 44 (9), Sep 1996, pp. 959-968. PMID 8773561

[1] Y. Gavrieli include: Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation. In: J Cell Biol . 119, 1992, pp. 493-501. PMID 1400587

[2] B. Grasl-Kraupp et al .: In situ detection of fragmented DNA (TUNEL assay) fails to discriminate among apoptosis, necrosis, and autolytic cell death: a cautionary note. In: Hepatology . 21 (5), May 1995, pp. 1465-1468. PMID 7737654

[3] A. Negoescu include: Importance of DNA fragmentation in apoptosis with regard to TUNEL specificity. In: Biomed Pharmacother . 52 (6), 1998, pp. 252-258. PMID 9755824

[4] F. Labat-Moleur et al .: TUNEL apoptotic cell detection in tissue sections: critical evaluation and improvement. In: J Histochem Cytochem . 46 (3), Mar 1998, pp. 327-334. PMID 9487114

[5] A. Negoescu include: In situ apoptotic cell labeling by the TUNEL method: improvement and evaluation on cell preparations. In: J Histochem Cytochem. 44 (9), Sep 1996, pp. 959-968. PMID 8773561