The monoclonal antibody JHD-7.10.1 reacts with human complement factor H-related protein 1 and 2 (CFHR1/2). In humans the complement factor H protein family consists of complement factor H, the factor H-like protein 1 and five factor H-related proteins termed 1 to 5. All members of this group are expressed primarily in the liver and subsequently secreted into plasma. The secreted forms of these proteins are composed exclusively of repetitive protein domains termed short consensus repeats (SCR). The CFHR1 proteinis composed of five SCR domains and circulates in plasma as two differentially glycosylated isoforms (37 kDa and 43 kDa). CFHR-2 is composed of four SCRs and is present in human plasma in a non-glycosylated form (24 kDa) and a glycosylated form of 29 kDa. So far the biological functions of both CFHR-1 and CFHR-2 proteins are poorly understood, however recent studies have shown that CFHR1 is a complement regulator that blocks C5 convertase activity as well as assembly and membrane insertion of the terminal components. Moreover, genetic variations in the CFHR1 gene are associated with several diseases such asatypical hemolytic uremic syndrome and age-related macular degeneration. Due to a high degree of amino acid sequence homology the monoclonal antibody is cross-reactive with both CFHR1 and 2. The antibody is suitable for immunoassay and Western blot applications.