Extraction of lipids from mammalian liver using nontoxic solvents

A simple method for extracting and purifying lipids from rat liver in a single step using nontoxic solvents is described. The method consists of homogenizing the puliverized tissue with a mixture of tricholotrifluoroethane (Cl₂CF-CClF₂) and isopropyl alcohol ($\text{1 : 1,}\text{v}\text{v}$). Just enough water is added to the lipid extract to produce a biphasic system. Pure lipid extract is obtained by isolating the lower layer from the aqueous upper phase which contains the non-lipid materials. The described method compares favourably with that of Folch et al., both quantitatively and qualitatively. The solvent system used also has the advantage of being less toxic than the widely used chloroform/methanol system, which makes it safer for prolonged use. The new method is simple, efficient and reproducible.