Xanthoprotein test

The xanthoprotein test. This is a characteristic reaction of proteins that contain phenyl rings... 

The xanthoprotein test. (Perform the experiment under the hood.) Place 15 drops of each of the following solutions in five clean, labeled test tubes ... 

Which of these metal ions gives a positive test with casein in milk Xanthoprotein test... 

Xanthoprotein Test.—Add 5 drops of concentrated nitric acid to about 3-5 ml. of protein solution. A precipitate forms if higher proteins be present (Heller s test). Heat the mixture. A yellow colour develops if the test be positive. Cool, and make alkahne with ammonium hydroxide. The colour deepens to orange. 

Gelatin is the commonest protein that does not give the xanthoprotein test owing to its lack of the necessary amino acids. 

Xanthoprotein reaction a qualitative test for protein, using concentrated nitric acid. The resulting yellow color is due to nitration of aromatic amino acid residues... 

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