Immunonephelometric determination of apolipoprotein A-1 in hyperlipoproteinemic serum.
The intensity of scattered light varies with the size of the scattering particles. Studying the quantitative immunonephelometric determination of apolipoprotein A-1 (apo A-1), we observed that the different particle sizes of lipoproteins must be taken into account in immunonephelometry if apo A-1 is a constituent of the lipoprotein particles. Because interaction between large lipoproteins and immunocomplexes of high-density lipoproteins increases light scattering nonspecifically, false estimations may be obtained in serum with excessive hyperlipoproteinemia. Furthermore, the accessibility of antigenic sites of apo A-1 in intact high-density lipoproteins is limited. Immunonephelometry of apo A-1 in serum necessitates therefore the elimination of various interferents, which we have achieved by a single one-step extraction of lipids in a two-phase liquid system. With n-hexanol/polyfluoro-polychloro-polyethylene, about 90% of the serum lipids are extracted and only apolipoprotein B is precipitated at the interphase. This pretreatment eliminates the interferences caused by excessive hypertriglyceridemia and therefore greatly facilitates the endpoint immunonephelometry of apo A-1 in normal and pathological serum samples.
D001053:Apolipoproteins / Q000097:blood* / Q000276:immunology; D001054:Apolipoproteins A; D005189:False Positive Reactions; D006801:Humans; D006951:Hyperlipoproteinemias / Q000097:blood*; D008075:Lipoproteins, HDL / Q000276:immunology / Q000302:isolation & purification; D008079:Lipoproteins, VLDL / Q000276:immunology / Q000302:isolation & purification; D009391:Nephelometry and Turbidimetry; D010316:Particle Size
D001053:Apolipoproteins; D001054:Apolipoproteins A; D008075:Lipoproteins, HDL; D008079:Lipoproteins, VLDL