STABILIZER OF CYTOKERATIN AND IMMUNOASSAY OF CYTOKERATIN USING THE SAME

PROBLEM TO BE SOLVED: To enable the highly reproducible immunoassay of cytokeratin CK 19 by using a specific emulsifier as a stabilizer. SOLUTION: An emulsifier in this invention means a substance capable of forming a micelle in a liquid state and, specifically, there are polyvinyl alcohol(PVC), casein, a nonionic or amphoteric surfactant or the like. A stabilizer is used in the coexistence with CK in a liquid state. For example, coexistent concn. is pref. 0.2-1% when PVC is used as the stabilizer and pref. 0.1-0.5% in the case of casein and pref. 0.2-1% in the case of the surfactant. The immunoassay of CK using the stabilizer means a measuring method using an anti-CK antibody and contains any known immunoassay such as radioimmunoassay, enzyme immunoassay, an agglutination measuring method or the like.