Immunohistochemical microquantitation method for type I collagen in kidney histological section of the rats

An immunohistochemical micromethod for quantitation of type I collagen in frozen histological section of rat kidney was developed. A principle of this method is enzyme-linked immunosorbent assay (ELISA). The intensity of immunoreactivity of the section to an anti-type I collagen antibody was quantitated, and then the total protein content in the same section was measured colorimetrically. Type I collagen content was expressed as mg of type I collagen per g of total protein. In this micromethod, the minimum area and optimum thickness of the section were 5 mm2 and 10 microns, respectively. Type I collagen content in the rat kidney section was 3.02 +/- 0.12 mg/g. This method should be useful for diagnosis of renal failure.