Thymol test is a test to determine the functional state of the liver. It is based on the property of a saturated solution of thymol in veronal buffer with pH = 7.8 to give turbidity with blood serum. The degree of turbidity is greater, the higher the content in the serum gamma globulins (with a simultaneous drop in the content of albumin). The degree of turbidity is usually determined by nephelometric, comparing the turbidity of the sample with the turbidity of a series of standard barium sulfate suspensions, one of which is taken as a unit. Normally, turbidity is from 0 to 4.7 units. Elevated thymol samples indicate an increase in blood concentrations of α-, β- and γ-globulins and lipoproteins, which is most often observed in liver diseases. At the same time, the thymol test is not completely specific, as it can be elevated in some infectious diseases and neoplasms.