ERCC1, also known as DNA excision repair protein ERCC-1, functions in the nucleotide excision repair pathway, and is required for the repair of DNA lesions such as those induced by UV light or formed by electrophilic compounds including cisplatin. Defects in ERCC1 are the cause of cerebro-oculo-facio-skeletal syndrome type 4 (COFS4). Recombinant human ERCC1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.