Anti-RFA2 (Ab-21) Antibody

Raised in rabbit against the 34 kDa subunit of human Replication Protein A, this polyclonal reagent from Antibodies.com targets RFA2 (also called RPA2) at an epitope centred near residue 21 of the protein. Supplied as 100 µL of unconjugated antiserum in a single vial, it is validated for western blot and immunohistochemistry on human samples and is well suited to studies of DNA replication stress and the DNA damage response.

RPA2 is the central subunit of the heterotrimeric single-stranded DNA binding complex that stabilises unwound DNA at replication forks and at sites of damage. The protein undergoes hyperphosphorylation by ATR and ATM kinases after genotoxic insult, producing a characteristic gel mobility shift that this antibody readily detects by western blot. The polyclonal nature of the reagent allows recognition of multiple epitopes around the N-terminal region, where several early phosphorylation sites cluster, so investigators can monitor both total RPA2 levels and its post-translational modification state across time-course experiments.

On human tissue sections, immunohistochemistry reveals nuclear staining that is most prominent in actively proliferating compartments undergoing S-phase or checkpoint activation. Researchers studying replication stress, genotoxin sensitivity, or homology-directed repair commonly pair this antibody with markers such as γH2AX, Chk1, and PCNA to map checkpoint engagement. Store the vial frozen at -20 °C in small aliquots to limit freeze-thaw cycles and preserve antibody titre over the reagent's shelf life.