Abstract: A lipopolysaccharide (LPS) and/or lipid A binding agent is provided. The LPS and/or lipid A binding agent contains an LPS and/or lipid A binding peptide, such as a peptide comprising an amino acid sequence of XYSSS (X=K, R, or H), or a derivative thereof, as an active ingredient. The LPS and/or lipid A binding agent is useful as, for example, an LPS and/or lipid A neutralizing agent or an LPS and/or lipid A removing agent.

Abstract: A lipopolysaccharide (LPS) and/or lipid A binding agent is provided. The LPS and/or lipid A binding agent contains an LPS and/or lipid A binding peptide, such as a peptide comprising an amino acid sequence of XYSSS (X=K, R, or H), or a derivative thereof, as an active ingredient. The LPS and/or lipid A binding agent is useful as, for example, an LPS and/or lipid A neutralizing agent or an LPS and/or lipid A removing agent.

Abstract: The present invention provides: an anti-idiotype antibody which can be conveniently and economically produced compared with the existing type; a method of producing the anti-idiotype antibody; and a method of preparing a target idiotype antibody using the anti-idiotype antibody. A substance capable of binding to an antigen-binding site of a first antibody is prepared and this substance is ligated to a second antigen to give a fused antigen. Next, this fused antigen is bonded to a second antibody capable of binding to the second antigen, thereby giving an anti-idiotype antibody against the first antibody. In a method of preparing the idiotype antibody including: inoculating an animal with an anti-idiotype antibody against a specific idiotype antibody; and then further inoculating the animal with an antigen of the above idiotype antibody, the anti-idiotype antibody of the present invention is employed. Thus, the target idiotype antibody can be efficiently obtained.