TUNEL
Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) is a method for detecting DNA fragmentation by labeling the terminal end of nucleic acids.
TUNEL is a common method for detecting DNA fragmentation that results from apoptotic signaling cascades. The assay relies on the presence of nicks in the DNA which can be identified by terminal deoxynucleotidyl transferase or TdT, an enzyme that will catalyze the addition of dUTPs that are secondarily labeled with a marker. It may also label cells that have suffered severe DNA damage.
Overall, TUNEL staining directly provides a measure of DNA fragmentation/nicks. This measure is often incorrectly interpreted as a measure of cell death, but viable cells may possess highly 'nicked' DNA as is the case during replication stress, or replication catastrophe.
TUNEL is a common method for detecting DNA fragmentation that results from apoptotic signaling cascades. The assay relies on the presence of nicks in the DNA which can be identified by terminal deoxynucleotidyl transferase or TdT, an enzyme that will catalyze the addition of dUTPs that are secondarily labeled with a marker. It may also label cells that have suffered severe DNA damage.
Overall, TUNEL staining directly provides a measure of DNA fragmentation/nicks. This measure is often incorrectly interpreted as a measure of cell death, but viable cells may possess highly 'nicked' DNA as is the case during replication stress, or replication catastrophe.