Influence of Sugars and Amines on the Colorimetric Hexosamine Method of Elson and Morgan and its Possible Elimination

Abstract

DURING the course of investigations on the chemistry of the jelly coat of sea-urchin egg^1,2, the analyses for hexosamine by paper partition chromatography³ were found to be negative in spite of the positive results obtained with the colorimetric method of Elson and Morgan⁴. This was found² to depend on an interaction of the sugars with the amino-compounds, especially lysine, of the hydrolysate, resulting in a red colour with the same absorption maximum (at 530 mµ) as for glucosamine. The interaction of mixtures of sugars and certain amino-acids, especially lysine and glycine, on the hexosamine reaction has been pointed out before (for example, refs. 5 and 6); but in these cases, where the hexosamine values were rather high compared with the interfering substances, the discrepancies were small. In our case, however, the error apparently is unusually high. Since in other biological material similar conditions may exist, we thought this communication might be of some value.