TR-FRET PARP1 Trapping Assay Kit

The TR-FRET PARP1 Trapping Assay Kit is designed to detect the poly-ADP-ribosylation activity of PARP1 and the status of PARP1 trapping on DNA. The DNA substrate in the kit is labeled with a fluorophore (acceptor). A Terbium (Tb)-labeled anti-Tag2 antibody binding to Tag2-Kras serves as the fluorescence donor. Activation of Tb results in fluorescence resonance energy transfer (FRET) if PARP1 binds to the fluorescence-labeled DNA, since the binding brings the fluorescence donor into close proximity with the fluorophore acceptor. Thus, the binding status can be quantitatively measured by calculating the ratio of the emission fluorescence intensities of the acceptor (665 nm) and the donor (620 nm). In the presence of NAD⁺, auto-PARylation of PARP1 leads to dissociation of PARP1 from the DNA, resulting in a decrease in the FRET signal. Conversely, inhibition of autoPARylation activity traps PARP1 on the DNA, and the FRET signal remains high.

Please contact us at for specific academic pricing.

Background

PARP1 (Poly (ADP-ribose) polymerase 1) is an abundant member of the PARP family and plays a crucial role in DNA repair by acting as a damage sensor and facilitator. It binds to DNA at the site of damage, becomes catalytically activated, and uses NAD⁺ as a substrate to add poly (ADP-ribose) (PAR) chains to itself and other proteins-a process called PARylation that results in the recruitment of other DNA repair proteins to the damaged site. Because of the high negative charge of PAR polymers, extensive autoPARylation of PARP1 leads to the dissociation of PARP1 from DNA, which isrequired for DNA repair completion. PARP1 is often overexpressed in various cancers, including breast, ovarian, prostate, lung, and glioblastoma. This overexpression is thought to support tumor cell survival. Some PARP inhibitors not only block the catalytic activity of PARP1 but also trap PARP1 on DNA at sites of damage, preventing its release. This creates a toxic DNA-protein complex that interferes with DNA replication and repair, leading to cell death-particularly in cancer cells deficient in homologous recombination repair (e.g., BRCA1/2-mutant cells).