Abstract
A human serum lipoprotein fraction with density greater than 1.210 has been separated by ultracentrifugation and found to contain about 8% of total serum phospholipid, non-phospholipid ester, presumably tri-glyceride, and little or no cholesterol. About half of the phospholipid was found to be in the form of lysolecithin, which in turn comprised about half of the total lysolecithin of serum.