RAD51 protein family assist in repair of DNA double strand breaks. RAD51 family members are homologous to the bacterial RecA and yeast Rad51. In humans, RAD51 is a 339-amino acid protein that plays a major role in homologous recombination of DNA during double strand break repair. RAD51 is involved in the search for homology and strand pairing stages of the process. RAD51 can interact with the ssDNA-binding protein RPA, BRCA2, PALB2 and RAD52. Recent studies using fluorescent labeled Rad5 has indicated that Rad51 fragments elongate via multiple nucleation events followed by growth, with the total fragment terminating when it reaches about 2 μm in length.