AQA A Level Biology复习笔记1.2.4 Biochemical Tests: Lipids

• The emulsion test that can be carried out quickly and easily in a lab to determine if a sample contains lipids
• This test is qualitative - it does not give a quantitative value as to how much lipid may be present in a sample
• Lipids are nonpolar molecules that do not dissolve in water but will dissolve in organic solvents such as ethanol
• Add ethanol to the sample to be tested, shake to mix and then add the mixture to a test tube of water
• If lipids are present, a milky emulsion will form (the solution appears ‘cloudy’); the more lipid present, the more obvious the milky colour of the solution
• If no lipid is present, the solution remains clear

The Emulsion test for lipids forms a milky colour.