Study Set Content:
The principle of Millon’s test is based upon the “Nitration” reaction. Millon’s test makes use of nitrifying agent i.e. concentrated nitric acid, by which the phenolic amino acids are converted into
nitrated amino acid
Used for the detection of amino acids containing guanidium groups
Sakaguchi Test
Used for the detection of aromatic amino acids eg. Tyrosin Tryptophan etc.
Xanthoproteic test
is specific for the detection of arginine.
Sakaguchi Test
The Sakaguchi test is based on the principle of (blank) reaction
Oxidation
Sakaguchi test makes use of oxidizing agent i.e.
sodium hydroxide and α-naphthol reagent.
s specific for the detection of aromatic amino acids containing active benzene ring or aromatic nucleus.
Xanthoproteic Test
reacts with the arginine
Both sodium hydroxide and α- naphthol
Both sodium hydroxide and α- naphthol reacts with the arginine to give a characteristic
red color
Both sodium hydroxide and α- naphthol reacts with the arginine to give a characteristic red color on the treatment with
hypochlorite
The Xanthoproteic test is based upon the principle of (blank) reaction.
Nitrification
In this test, the active aromatic amino acids undergo nitrification in the presence of concentrated
nitric acid
The Xanthoproteic test is based upon the principle of “Nitrification” reaction. In this test, the active aromatic amino acids undergo nitrification in the presence of concentrated nitric acid which forms a
yellow-colored nitro-derivatives.
Sakaguchi test positive result
Gives red color
Xanthoproteic test positive result
Gives yellow color solution
s specific for the detection of amino acids like histidine and tyrosine.
Pauly’s Diazo Test
Is specifically used to detect the presence of Histidine.
Histidine Test (Knoop test for histidine)
The principle of Pauly’s diazo test is based upon the (blank ) reaction
“Diazotization”
Pauly’s diazo test makes the use of chemical reagent
Sulphanilic acid
Pauly’s diazo test makes the use of chemical reagent (Sulphanilic acid) in the presence of
sodium nitrite and hydrochloric acid.
