Salkowski test (for cholesterol)
Salkowski test is used to detect cholesterol in a solution. This test is named after a German biochemist Ernst Leopold Salkowski. Cholesterol solution in chloroform when shaken with equal volumes of concentrated sulphuric acid and layers allowed to separate by standing, the chloroform layer turns red.
- Cholesterol solution
- Concentrated Sulphuric acid
- Separate the egg yolk (yellow part) of a boiled egg and grind it with about 50 ml of chloroform in a mortar.
- Filter the suspension through a filter paper.
- The filtrate is the cholesterol solution. The egg yolk is the rich source of cholesterol.
- Take 1 ml of cholesterol solution in chloroform in a dry test tube.
- Add 1 ml of concentrated sulphuric acid. The two layers do not mix.
- Shake the tube to mix the two layers.
- The upper layer i.e. chloroform layer turns red.
- The lower layer i.e sulphuric acid layer turns yellow colour with green fluorescence.
- The upper layer consisting of chloroform becomes bluish-red to cherry-red, whereas the layer of sulphuric acid becomes yellow with green fluorescence.