Test for Lipids
| Test | Observation | Basis of test |
| Sudan III Sudan III is a red dye. Add 2ml oil to 2 ml of water in a test-tube. Add a few drops of Sudan III and shake. |
A red-stained oil layer separates on the surface of the water, which remains uncolored. | Fat globules are stained red and are less dense than water |
| Emulsion
test Add 2 ml fat or oil to a test tube containing 2 ml of absolute ethanol. Dissolve the lipid by shaking vigorously. Add an equal volume of cold water. |
A cloudy white suspension. | Lipids are immiscible with water. Adding water to a solution of the lipid in alcohol results in an emulsion of tiny lipid droplets in the water which reflect light and give a white,opalescent appearance. |
| Grease
spot test Rub a drop of the sample into a piece of paper. allow time for any water to evaporate. Gentle warming will speed up the process |
A permanent transparent spot on the paper. | ¡@ |