The mercuric chloride turbidity test

Abstract

1. 1. Some of the factors concerned with the Takata-Ara reaction have been investigated. It is suggested that the test is best conducted in the neighbourhood of pH 12.3 in phosphate buffer at a final ionic strength of 1.0. 2. 2. Of the common metallic salts which can be used under these conditions only those of mercury and silver have shown any differentiation between hepatitis and normal sera. This may be correlated with the instability of the hydroxides of these two metals. 3. 3. On the basis of these experiments, a new technique for the determination of HgCl 2 turbidity is proposed which gives normal limits of from 0–4 units. 4. 4. Experiments with bovine and human serum proteins have shown that the reagent is precipitated by the β- and γ-globulin fractions. The influence of albumen may be either inhibitory or enhancing according to its relative concentration. 5. 5. The results of the test have been tabulated in 279 patients suffering from a variety of diseases. It appears to be a sensitive indicator of hepatic cirrhosis, but is also positive in a variety of liver diseases and in certain other conditions. 6. 6. The test shows a fairly close correlation with the zinc sulphate test; it is, however, more sensitive and less specifically related to liver damage. There is a definite but less close correlation with the thymol turbidity test, and with the A/G ratio. 7. 7. The mercuric chloride turbidity test appears to be of value in the diagnosis of hepatic cirrhosis, and in the investigation of liver damage in other conditions.