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Experiments on a quantitative and qualitative test for anti-beriberi vitamine

1920; SAGE Publishing; Volume: 17; Issue: 8 Linguagem: Inglês

10.3181/00379727-17-93

1535-3702

Casimir Funk, Harry Dubin,

Metabolism and Genetic Disorders

In 1912 one of us (C.F.) experimented with the anti-beriberi vitamine to see if it could not act as coferment in alcoholic fermentation. The experiments failed at that time, but now the subject through the work of Williams, Bachmann and Eddy has attained a new interest. Their results seem to prove that vitamine activity can be measured by growth of yeast cells and would permit of dispensing with animal experimentation in the initial stages of vitamine fractionation. Because of the uncertainty of the Bachmann fermentation test, and the complicated procedure of Eddy's test, it was thought desirable to develop a simple macro method. Our procedure is as follows: A yeast suspension is prepared according to the method of Eddy by shaking a loopful of 48 hours yeast culture in a definite amount of Naegeli's solution for 4 hours on a shaking machine. Duplicate tubes are then prepared containing: (1) yeast suspension + Naegeli, (2) vitamine sol. + Naegeli, and (3) vitamine sol. + yeast suspension + Naegeli. The tubes are incubated for 20 hours at 30° and the fermentation then interrupted by heating to 70° for a few minutes. The contents of the test tubes are then transferred to special centrifuge tubes, the bottom part of which ends in a capillary 2% cm. in length and divided in mm. The tubes are centrifuged at 2600 r.p.m. for 15 min. and the reading made without much delay as there is a tendency for the yeast cells to swell up slightly after a time. Sterility during the entire process, excepting centrifugation, is of paramount importance. The results obtained with this method were as follows: The procedure was so well standardized that the controls with yeast suspension alone were practically constant.