Abstract: Provided are a monoclonal antibody making it possible to detect a native fibrin monomer, which is produced at the initial state of blood coagulation, and soluble fibrin; a hybridoma; and an immunoassay for detecting the initial stage of blood coagulation with high sensitivity, quickly, using the monoclonal antibody. Using a fibrinogen analog in blood as an immune source, cell fusion is carried out to prepare a monoclonal antibody which is not reactive with fibrinogen and is specifically and simultaneously reactive with a native fibrin monomer (that is, a fibrin monomer which is present in a body fluid, in particular in blood, and is not solubilized) and soluble fibrin. The fibrin monomer analog is preferably fibrinogen treated with bathroxobin, which is a snake venom.

Abstract: Provided are a monoclonal antibody making it possible to detect a native fibrin monomer, which are produced at the initial state of blood coagulation, and soluble fibrin; a hybridoma; and an immunoassay for assaying the initial stage of blood coagulation highly sensitively, and promptly, using the monoclonal antibody. Using a fibrinogen analogous compound in blood as an immune source, cell fusion is carried out to prepare a monoclonal antibody which is not reactive with fibrinogen and is specifically and simultaneously reactive with a native fibrin monomer (that is, a fibrin monomer which is present in a body fluid, in particular in blood, and is not solubilized) and soluble fibrin. The fibrin monomer analogous compound is preferably fibrinogen treated with bathroxobin, which is a snake venom.

Abstract: An immunoagglutination reagent includes liposomes, as a carrier, with a covalently bound antigen or antibody immobilized thereon. The reagent is used to assay an antibody or an antigen on the basis of agglutination. The assaying can be done at a high sensitivity in the short wave region where the change in turbidity caused by the agglutination is enhanced. An antibody or an antigen is immobilized onto the surface of the liposome, and a water-soluble polymer compound or a gelled compound is entrapped in the liposomes. The substance entrapped in the immunoagglutination reagent enhances the change in turbidity via the agglutination caused by the antigen-antibody reaction.