Removal of haem from lipids extracted from intact erythrocytes with particular reference to polyphosphoinositides

With the use of a modified acid version of a current lipid-extraction technique [Bligh & Dyer (1959) Can. J. Biochem. Physiol. 37, 911-917], 92% of phosphatidylinositol 4,5-bisphosphate obtained by means of three sequential extractions from intact human erythrocytes was obtained during the first one. Some 95% of the haem co-extracted with the lipids could then be removed, with a maximal loss of polyphosphoinositides of less than 3%. About 58 nmol of phosphatidylinositol 4,5-bisphosphate was found per ml of erythrocytes.