Lipid sovent systems are not equivalent for analysis of lipid classes in the microeukaryotic green alga, Chlorella

A comparison of three lipid solvent system indicated that they are not equivalent for the analysis of lipid classes in the green alga, Chlorella. Soxhlet extraction (methylene chloride/methanol, 3 h refulx) recovers more neutral lipid than the other methods but is equivalent to the room-temperature Bligh and Dyer (chloroform/methanol/water) extraction modified with phosphate buffer in glycolipid and polar lipid recovery. The Soxhlet method, however, gave a significantly lower recovery of many polyunsaturated fatty acids. The hexane/isopropanol method is selective for algal neutral lipids with poor recovery of membrane lipids (glyco- and polar lipids). Although this selectivity may have some useful applications, for biochemical studies of lipid synthesis in Chlorella, the modified Bligh and Dyer provides the most quantitative and reproducible recovery of all Chlorella lipid classes while minimizing artifacts due to the extraction procedure.