Ultracentrifugal isolation of serum chylomicron-containing fractions with quantitation by infrared spectrometry and NCH elemental analysis.

An ultracentrifugal method for isolating chylomicron-containing fractions from serum by flotation, using either standard Spinco swinging-bucket rotors or a specially fabricated swinging-bucket rotor, is described. Lower limits of the S(f) rates of the chylomicron fractions are evaluated using a computer technique to define lipoprotein flotation over a nonlinear NaCl density gradient. The latter is prepared by a special overlayering technique.Quantitation within a 9-50 mug region of mass assay is accomplished by both infrared spectrometry and elemental analysis for N, C and H. Results indicate that the chylomicron concentration in serum for a small population of nonfasting male adults ranges from approximately 0-50 mg %.