[Research for development of immunoassay kits for hapten]

Determination of estrogen concentrations in the urine is widely utilized for a variety of purposes, such as the assessing of fetoplacental unit function and ovarian function, and the monitoring of follicle in inducing ovulation in the treatment of infertility. Since hapten antigens such as estrogen have low molecular weight, unlike high molecular substances, they do not form visible agglutination of antigen-antibody reaction, so there has been no other choice but to depend on radioimmunoassay for the determination of estrogen concentrations. However, radioimmunoassay requires special facilities and apparatus and is complicated in procedure, and these drawbacks have prevented the estrogen assay from routine tests in spite of clinical usefulness. As a result of various researches, a new immunochemical principle called competitive agglutination inhibition reaction has been developed for the determination of hapten concentrations, and succeeded in putting this principle to practical use with a fetoplacental unit function test kit (Estrotec slide test) and highly sensitive semi-quantitative analysis kits for urinary estrogen (Hi-estrotec and Hi-estrotec slide).