1. Biuret Test
- chemical test for detecting presence of peptide bonds in the presence of peptides
- Positive visible result: violet
- shows positive test for alpha amino acids and proteins that contain free amino acid groups
- Positive visible result: deep blue or purple color
Xanthoprotein - yellow acid substance formed by the reaction of hot HNO3 on albuminous or protein matter and is changed to a deep orange-yellow color by the addition of NH3
1. Millon's Test for Tyrosine
- a test developed by Auguste Millon, a French chemist
- This test is not specific for proteins. It detects phenolic compounds. A reddish-brown coloration or precipitate indicates the presence of tyrosine residue.
- positive visible result: purple ring in the junction where the two liquids meet
-positive result: red