In Zeitschrift fur Immunitatsforschung und experiment. Therapie, volume No. 49, 1926, and in the Medical Gazette, No. 2, 1926, an article by L. G. Peretz "Experience in developing a biological response to lipoids" was published. According to the author, the principle of the method he proposes, the biological method, is as follows: Back in 1901, Ramson showed that saponin gives a strong connection with cholesterol. Another well-known fact is that saponin causes hemolysis. The reason is its connection with erythrocyte lipoids and the resulting destruction of their stroma. Combining these two phenomena in that they have something in common, that is, saponin, we get the basis for the reaction to cholesterol, and if it turned out that saponin gives a connection with other lipoids, then other lipoids. An experiment that can prove the correctness of this reasoning consists in the following: a solution of saponin is added to the cholesterol solution, and after a certain period of time, a suspension of erythrocytes. Hemolysis does not occur. In the control tube (without cholesterol), hemolysis is obtained.