The experimental generation of antibodies to alpha-melanocyte stimulating hormone and adrenocorticotropic hormone.

Sensitivity, reproducibility, and specificity are requirements for a suitable assay for hormones. The quantitation of a-MSH 1 is currently based on a technique devised in 1954, which utilized isolated pieces of frog skin (1). In the presence of a-MSH, frog skin darkens with a measurable decrease in the reflection of light from the skin. Although this assay possesses great sensitivity (less than 10-1" g of a-MSH), it does not have the degree of specificity necessary to discriminate among the several substances that darken frog skin, such as ACTH and aand ,8-MSH. This lack of specificity has prevented application of the in vitro frog skin assay to clinical problems. Immunochemical techniques have become useful for the measurement of several small polypep-