Terminal deoxynucleotidyl transferase-mediated

Terminal Deoxynucleotidyl Transferase-Mediated dUTP Nick End Labeling... 

TUNEL The TUNEL assay represents a historical low point in attempts to coin acronyms. The Terminal deoxynucleotidyl transferase mediated dC/TP Nick End-Labeling assay labels the ends of DNA with fluorescent UTP. Apoptotic cells often have fragmented DNA these fragments will provide more substrate for the enzyme terminal deoxynucleotidyl transferase. Apoptotic cells can therefore be enumerated by flow cytometry according to their increased intensity in the TUNEL assay. 

Fig. 2. Rat mammary gland, 3-4 d postweaning, stained by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. The nuclei of the apoptotic cells are stained dark. Nonapoptotic cell nuclei are counters tained with hematoxylin (pale).

TUNEL Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling... 

Seven-week-old Wistar rats at normal iodine basehne were divided into four different groups and fed on water of normal, 1.5-fold, 3-fold and 6-fold iodine levels for 8 months. Transmission electron microscope, flow cytometry, DNA quantitation and annexin V early apoptosis detection technique were combined to evaluate intracellular ROS level expression of apoptosis-related molecules (Fas, FasL, bcl-2, bax) was traced by indirect fluorescent stained flow cytometry and immunohistochemistry qualitative and quantitative analyses of cell apoptosis were performed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. 

A very sensitive method is the TUNEL assay (terminal deoxynucleotidyl transferase mediated dUTP-biotin end-labelling), that allows the direct... 

It has been shown that CLA was able to protect against 2-amino-3-methylimida-zo[4,5-/]quinoline-induced colon carcinogenesis in F344 rats (25). A recent study (26) demonstrated that 1% dietary CLA significantly decreased colon tumor incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats, and the apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick... 

Biochemically, apoptosis is characterized by the internucleosomal degradation of chromosomal DNA to form a series of double-stranded fragments that are multiples of 180 200 base pairs in length. These fragments give a characteristic DNA ladder pattern on gel electrophoresis [91, 92] and can be detected by several cytochemical methods, the most extensively used being the terminal deoxynucleotidyl transferase (TdT)-mediated biotinylated dUTP nick end labeling (TUNEL) [93-95], The detection of ladder pattern and TUNEL positivity has been adopted as a marker of apoptosis. 

Another common method for measuring apoptosis is the DNA labeling technique, terminal deoxytransferase-mediated dUTP nick-end labeling (TUNEL). In this method, labeling of DNA strand breaks at the 3 end is achieved by using the enzyme, terminal deoxynucleotidyl transferase (TdT) and either a radioactive or a fluorescently-Iabeled deoxynucleotide. This method provides a very sensitive measurement of DNA strands breaks. However, as DNA strand... 

Although more labor intensive than the acridine orange method, the TUNEL-labeling technique (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP nick end labeling) provides a permanent record for labeling dead cells. (From Gavrieli et al. 1992 White et al. 1996 protocol and additional modifications were provided by P. Kurada and Kristen White.)... 

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