Mannan-binding lectin (MBL), also called mannose-binding lectin or protein, belongs to the C-type family of collectins, showing calcium-dependent binding to certain sugars. It consists of oligomers of triple-chain subunits and its binding and complement activating activities depend on its normal oligomerization. On binding to mannan-like microbial surface carbohydrates,Mouse,BL activates the complement system by means of its own lectin pathway, depending on the MBL-associated serine proteases (MASPs). Because of the presence of different structural and promoter alleles in the population, 12% or more of the population have low concentrations (<50ng/mL) of normally oligomerized, functional MBL in plasma or serum. This antibody is specific for human MBL from plasma or serum, but cross-reacts strongly with MBL from horse and swine.