three immunochemically and electrophoretically distinct lipoproteins , lp-a , lp-b , and lp-x , ( 1 ) were isolated from the low density lipoprotein fraction ( 1.006-1.063 g/ml ) in plasma from patients with biliary obstruction by a separation procedure which combines ultracentrifugation , heparin precipitation , and ethanol fractionation .
C0023820
lipoproteins
C0065058
lp-a