A method of immunoassaying a human tau protein present in a human cerebrospinal fluid by using an antibody immobilized on an insoluble support and a labeled antibody, each antibody having a recognition site in the amino acid sequence region ranging from the 251st to the 441st amino acid residues of a human tau protein; and an immunoassay kit therefor. These method and kit enable the concentration of a human tau protein of a normal man and that of a patient with central nerve cytopathy to be determined discriminatively at high sensitivity. Hence the assay results can be utilized for the test, study or diagnosis of patients with central nerve cytopathy.
METHOD OF ASSAYING HUMAN TAU PROTEIN, KIT THEREFOR, AND DIAGNOSTIC METHOD