BLM, a helicase protein from the RecQ subfamily, participates in DNA replication and repair with a magnesium-dependent ATP-dependent DNA-helicase activity that unwinds single- and double-stranded DNA in a 3'-5' direction. BLM is part of the BRCA1-associated genome surveillance complex (BASC), which contains BRCA1, MSH2, MSH6, MLH1, ATM, BLM, PMS2 and the RAD50-MRE11-NBS1 protein complex. Defects in BLM are the cause of bloom syndrome, characterized by growth deficiency, skin pigmentation disorders, predisposition to malignancy and chromosomal instability.The synthetic peptide used to raise the antibody Cat. No. 200159 is selected from a sequence within the N-term region of human BLM. For blocking experiments, a 10 to 100 fold molar excess to antibody is recommended.