Kelinda Tucker

Because of the divergency of opinion regarding Botelho's serum reaction the following work was carried out in this laboratory. Samples of cancer serum, normal serum, animal serum, proteins and amino acids were investigated. M. Giauni (1) reports 71 per cent positive results with carcinoma serum by use of this reaction. G. Fischera (2) also used this test and obtained a positive reaction in 80 per cent of patients with malignant tumors. The technique used was as follows. The serum was diluted with an equal volume of physiological salt solution. To 0.5 cc. of this there were added 2 cc. of 5 per cent citric acid, 1 cc. formalin, water to make 100 cc; finally, 7 cc. of a solution of iodine in potassium iodide (iodine 1.0, potassium iodide 2.0 parts, distilled water to make 210 parts). With negative reaction the fluid remains clear; positive reaction is shown by varying degrees of darkening up to a definite precipitation of a dark deposit. Fifty samples of cancer sera and eight of non-cancerous sera were examined. All cancer sera gave a positive reaction as evidenced by a dark red precipitate forming. The quantity of this precipitate varied but there was no connection between the severity of the disease and the amount of precipitate. The amount of precipitate which was formed increased with time. Some sera yielded a slight precipitate at first but after one or more hours the precipitate grew considerably. Also the time of settling of the precipitate varied with the different sera. All of the non-cancerous sera also gave a definite precipitate. In fact, some samples of the normal sera yielded a larger precipitate than any of the cancer sera.