Current Comment

A COLOR TEST FOR MALARIA  After reviewing Henry's theory of immunity in malaria and Henry's melanoreaction, Proske and Watson¹ have described a protein tyrosine test which they consider valuable in the diagnosis of malaria. The principal reagents consist of sodium sulfate solution, sodium hydroxide solution, tyrosine standard solution and the phenol reagent of Folin and Ciocalteu. This test, when serums are used, they assert, gives a simple accurate colorometric reading which obviates the necessity for a photometer, which was required by the Henry serodiagnostic test. The procedure is based on the fact that proteins possess a chromogenic property which can be measured quantitatively against the color produced by pure tyrosine in the presence of a phenol reagent. This chromogenic value is constant for a given protein and the intensity of the color produced can be used as a measure of the amount of protein examined. The tyrosine chromogenic index