| 摘要 |
The invention relates to a method for the determination of lipid-bound sialic acid content of blood, primarily of human blood, in which serum is diluted with water, then extracted with a water-immiscible organic solvent or solvent mixture to remove neutral lipids, a lipoprotein fraction containing lipid-bound sialic acid is precipitated from the aqueous phase, the precipitated lipoprotein fraction is redissolved, a mineral acid, a copper(II) salt and resorcine are added to the solution, and the lipid-bound sialic acid content of the serum is calculated on the basis of the colour reaction produced with resorcine. According to the invention a) dextrane with a molecular weight of 10,000 to 20,000 is applied as precipitating agent in a solution with a concentration of 15-35 mg/100 ml and precipitation is performed at a pH of 5.8 to 7.5, or b) polyethylene glycol with a molecular weight of 4,000 to 10,000 is applied as precipitating agent in a solution with a concentration of 15-55 g/100 ml and precipitation is performed at a pH of 9 to 11, or c) a water-soluble manganese(II) salt is applied as precipitating agent in a solution corresponding to a Mn<2+> ion concentration of 8.7-13 g/100 ml and precipitation is performed at a pH of 5.5 to 7.5. |
