Extraction of a calcium-phospholipid-phosphate complex from bone

A calcium-phospholipid-phosphate complex with a constant 1:1 calcium to total phosphate molar ratio is shown to exist in rabbit and calf bone. This complex, which may be involved in the transport and deposition of bone mineral, appears to constitute a significantly greater proportion of the lipids of younger bone than of more mature bone. The comples was isolated by a modified Folch extraction employing ultrasonic disruption of cellular material. Evidence is presented to show that the complex is a natural constituent of bone rather than one created artifactually during extraction.