The monoclonal antibody 7G1 recognizes human M-ficolin, also known as ficolin-1. Ficolins are a family of pattern recognition molecules containing both a collagen-like domain and a fibrinogen-like domain that are capable of activating the complement system, through association with MASPs, on the surface of microorganisms. In human, three Ficolins are known: M-Ficolin, L- Ficolin (Ficolin-2), and H-Ficolin (Ficolin-3). M-Ficolin, is mainly expressed by- monocytes, granulocytes and- lung cells and is present locally in areas of inflammation. However, it was recently also found in serum suggesting that M-Ficolin also has a role in systemic immunity like L- and H-Ficolin. Functional analysis of M-Ficolin has demonstrated that it’s ligand is sialic acid present on bacteria since binding was abolished by prior treatment of the bacteria with sialidase. Furthermore, it was shown that M-ficolin facilitates the uptake of E. coli- by a leukemic monocyte lymphoma cell line, suggesting that it functions as a phagocytic receptor on the surface of circulating monocytes. Low cord blood concentration of M-ficolin has been- associated with higher necrotizing enterocolitis-associated fatality and two identified SNPs in the M-ficolin gene are associated with the development of rheumatoid arthritis. The monoclonal antibody 7G1 is suitable for use in immunoassays and western blotting. -