Tests for the presence of aromatic amino acids (proteins containing aromatic rings)
Indication of positive results: Formation of yellow color upon the addition of concentrated nitric acid
Wagner's Test
Tests for the presence of alkaloids
Indication of positive results: Formation of a brownish-red precipitate
Concentrated Sulfuric Acid Test
Tests for the presence of flavonoids
Indication of positive results: Formation of various color changes (typically ranging from yellow to orange to red) depending on the specific flavonoid present
Gelatin Test
Tests for the presence of tannins
Indication of positive results: Formation of a white precipitate
Sodium Hydroxide Test
Tests for the presence of flavonoids
Indication of positive results: Yellow coloration
Salkowski Test
Tests for the presence of terpenoids or steroids
Indication of positive results: Development of a reddish-brown coloration
Keller-Killiani Test
Tests for the presence of glycosides, particularly cardiac glycosides
Indication of positive results: Formation of red color
Frothing Test
Tests for the presence of saponins
Indication of positive results: Formation of froth upon shaking
