Question: is ninhydrin test for proteins?
Answer: Ninhydrin Test: The Ninhydrin Test is a test for amino acids and proteins with a free -NH2 group. When such an -NH2 group reacts with ninhydrin, a purple-blue complex is formed. ... The production of a yellow colored product upon the addition of nitric acid is a test for the presence of tyrosine or tryptophan in a protein.