Contamination of distilled water with free and bound amino acids and with microbes has been overlooked in most laboratories. Unless special precautions are taken, distilled water will be contaminated with air borne microbes, probably psuedomonads, which multiply in water of conductivity quality. Amino acids and proteins that may be found in the water therefore presumably are derived from these airborne organisms. Chemical reagents such as hydrochloric acid and ammonium hydroxide solutions, which have water as an integral part, also have been found to be contaminated with amino acids. This paper deals with the extent of such contamination and describes means to provide water and hydrochloric acid (6 mol/liter) that would be suitable for determination of amino acids in concentrations of 10-9 mol/liter or less in materials of biological interest as well as rocks, lunar soil, meteorites, etc.

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The inhibitory effects of 2-deoxy-D-glucose (2DG) and 6-deoxy-6-fluoro-D-glucose (6FG) on the metabolism of glucose by yeast were compared and some properties of the glucose transport system were examined. 2DG and 6FG had similar effects on the consumption of oxygen and the production of carbon dioxide by several strains of yeast, hence they appear to inhibit metabolism of glucose by the same mechanism. Kinetic studies with mixed inhibitors indicated that both compounds compete at the same catalytic site. The rate of entry of 6FG into the yeast cell and its equilibrium concentration were similar to those of galactose. The fermentation of D-galactose was strongly inhibited by 2DG and 6FG, and weakly inhibited by 2-deoxy-D-galactose and 6-deoxy-6-fluoro-D-galactose. The latter two compounds did not inhibit the fermentation of D-glucose.

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The strain-specific (Sp-M) and the cross-protective (X-M) antigens of type G1 cocci were isolated from RNase-treated cell walls and purified by ammonium sulfate fractionation, carboxymethylcellulose and Sephadex G-200 column chromatography and polyacrylamide gel electrophoresis. Acid hydrolysis resulted in fragmentation of the antigen molecules, but precipitin and bactericidal tests established that the major serologic activity characteristic of the native antigens, with minor exceptions, remained intact. The purified antigens absorbed their corresponding antibodies to yield specific antisera whose bactericidal activity correlated with bands of precipitate in agar gel diffusion tests. It was established that the X-M antigen has specific as well as cross-reactive activity, a determination which it was impossible to make before the purified material became available. The purified antigens with which antisera were absorbed had a ratio of O.D. 280 nm to O.D. 260 mn of 0.79 for the Sp-M and 1.00 for the X-M. The molecular size of the Sp-M was greater and the charge smaller than those of the X-M. Also, it contained twice as much glycine and half as much aspartic acid. The average ratio of lysine and arginine for the Sp-M and X-M was 2.3 and 1.5, respectively. The observation is of interest because it has been established in other work that the Sp-M requires a free ε-NH2 group of lysine and a free guanidino group of arginine for its serologic activity. The X-M antigen does not. The antigens were extractable as separate entities at pH values from 2 to 10 and at temperatures of 37°C and 100°C, thus demonstrating that they do not arise only by acid hydrolysis of a larger molecule with Sp-M and X-M serologic activity and may indeed exist as separate antigens on the cell wall. The molecules in alkaline extracts were larger than those in acid extracts. Acid hydrolysis of the alkaline preparation yielded products whose gel electrophoretic pattern was similar to that of the acid-extracted material. Therefore, it was possible to conclude that the smaller molecules of the latter were the result of acid hydrolysis and not the other procedures employed.