[Analysis of free cholesterol levels in human serum using holotoxin A1].

Triterpene glycosides from holothurians holotoxin A1, stichoposides C and D were used for assay of blood serum free cholesterol instead of digitonin. Blood serum lipids were extracted by a mixture of acetone-ethanol (1:1). Free cholesterol was precipitated from the extract after addition of the glycosides and analyzed in reactions with acetic anhydride, acetic and sulfuric acids.