A QUANTITATIVE METHOD FOR MEASURING MELANOPHORE EXPANDING ACTIVITY1

Abstract

An objective photoelectric method for the quantitative measurement of melanophore expansion in frogs is described. Data are treated statistically to determine the precision and accuracy of the method. Using an ACTH preparation as a source of melanophore expanding principle, a linear log dose-response relationship was obtained over the range of 0.064 to 6.4 [mu]g/frog. The slope, standard deviation, and degree of precision of the regression were relatively constant over a 6-month period.