Guava TUNEL Assay
for detection of late-stage apoptosis
One of the hallmarks of late stage apoptosis, or programmed cell death, is the fragmentation of nuclear chromatin. The DNA degradation generates DNA strands with exposed 3'-hydroxyl ends.
Quantitative fluorescence assay
The Guava® TUNEL Assay detects apoptosis-induced DNA fragmentation through a quantitative fluorescence assay. Terminal deoxynucleotidyl transferase (TdT) catalyzes the incorporation of bromo-deoxyuridine (BrdU) residues into the fragmenting nuclear DNA at the 3'-hydroxyl ends by nicked end labeling. A TRITC-conjugated anti-BrdU antibody can then label the 3'-hydroxyl ends for detection by a Guava System. The assay distinguishes two populations:
Non-apoptotic cells (TUNEL-negative)
Apoptotic cells (TUNEL-positive)
Key features include
Tube- and 96-well plate protocol
Analysis of DNA strand breakage in single cells
Works with adherent and suspended cells
Staining and data acquisition in 3-4 hours
Provides direct, absolute cell counts and population percentages
Data compatible with third party analysis software
Runs on Guava PCA, PCA-96, EasyCyte Mini, and EasyCyte Plus Systems
