A known weight of extracted lipids (approx. 100 mg) was dissolved in chloroform (1 ml) and fractionated by using a column (25 mm x 100 mm) of silicid acid (1 g), activated by heating overnight at 80 °C. Successive applications of dichloromethane (100 ml), acetone (100 ml) and methanol (50 ml) produced fractions containing neutral lipids, glycolipids plus sphingolipids and phospholipids, respectively. The weight of each fraction was determined after evaporation of the respective solvent.