2.10. Total lipid content
Total lipids were extracted using the method of Bligh and Dyer (1959) with a slight modification. About 1 g of skin samples was cut into pieces and extracted with 24 mL of chloroform–methanol (2:1 v/v) at 65 C for 3 h. The extract was filtered through mediumspeed qualitative filter paper and 6 mL of water were added. The aqueous layer was removed and the lipid extract was concentrated. The concentrated lipids were redissolved in chloroform–methanol,added with 15 g Na2SO4, filtered, and dried under reduced pressure.