The Identification and Estimation of Hexoses in Polysaccharides and Glycoproteins by the Carbazole Method

The Ultracentrifugal Analysis of Diphtheria Proteins.

“…As Pope has emphasized, the two parts of the molecule cannot be considered as Svedberg units, since they differ in antitoxic potency and stability to heat as well as in size. Moreover, it has been shown by Hewitt (4) and by ourselves (9) that purified antitoxic pseudoglobulin and specific toxin-antitoxin floccules contain about 2.6 per cent of carbohydrate calculated as mannose-galactoseglucosamine; and preliminary determinations by the method of Gurin and Hood (2) indicate that this carbohydrate moiety remains with the antitoxic portion of the molecule after digestion with pepsin. The carbohydrate content of the active fraction is increased to 3.8 per cent.…”

The Nucleic Acid and Carbohydrate of Influenza Virus

“…Carbazole Color Reaction.--It appeared unlikely that sufificient quantities of virus carbohydrate of adequate purity could be readily obtained in order to identify the component sugar or sugars by the classical approach of isolation and preparation of characteristic derivatives. However, the results obtained by Gurin and Hood (32,33) in a study of the colors developed by various sugars in the presence of carbazole and sulfuric acid seemed to offer promise, for this method requires only 0.1 mg. or less of carbohydrate and the carbohydrate need not be pure. The use of the carbazole reaction to identify sugars is based on the fact that the colors produced by the various sugars are significantly different, varying from pink to brown.…”

“…The carbazole employed was put/fled by twice washing with cold sulfuric acid and recrystallization from toluene and 70 per cent ethyl alcohol (32). The colors were developed as described by Gurin and Hood (32) and were then analyzed in the Beckman spectrophotometer at wave lengths of light ranging from 380 to 600 m/t with intervals of 20 nag.…”

“…It is clear that the individual sugars give distinctive and characteristic curves. From the spectrophotometer data, ratios of the optical densities of the colored solutions at two selected wave lengths can be calculated (32,34). These ratios, though they may vary by as much as 10 per cent between laboratories (cf.…”