The solvent pair performs two complementary tasks within the same preparation. Chloroform and methanol help disrupt biological membranes while creating conditions that dissolve lipid molecules from cells, tissues, or microorganisms. This combination allows membrane-associated lipids to move into the extraction mixture, making them available for subsequent biochemical or analytical measurements.
After the biological material is mixed with the solvents, adding water or a salt solution creates distinct liquid phases. Most lipids partition into the lower organic layer, whereas polar compounds preferentially remain in the upper aqueous layer. This physical separation reduces mixing between chemically different components and helps researchers recover lipid-rich material for analysis.
Water or a salt solution promotes the formation of separate aqueous and organic layers after the initial solvent treatment. That separation organizes the sample according to the chemical properties of its components: lipid molecules concentrate mainly in the lower organic phase, while polar substances remain above. The added solution therefore supports selective recovery rather than simply diluting the sample.
The recovered material can include phospholipids, triglycerides, sterols, and other lipid classes. Because these molecules differ in biological function and distribution, their combined recovery provides a broader picture of lipid composition than focusing on a single class. Researchers can use the resulting extract to examine membrane constituents, stored lipids, or lipid-related biochemical changes.
A typical workflow begins by preparing a tissue or cell lysate and mixing it with chloroform and methanol. The solvent treatment disrupts membranes and dissolves lipids. Water or a salt solution is then added to promote phase separation, after which the lower organic layer containing most recovered lipids can be collected for biochemical or analytical examination.
This approach is useful when investigators need to examine lipid composition or lipid-associated changes in cells, tissues, or microorganisms. The extract can support studies of membrane composition, metabolism, and signaling, as well as investigations of lipid-associated disease. Its value comes from converting complex biological material into a lipid-enriched fraction suitable for further analysis.