Despite the necessity for [beta]-quantification in some clinical trials, drawbacks to its usefulness include the need for large specimen volumes, complex handling steps, and long ultracentrifugation times.
All ultracentrifugation equipment and supplies were from Beckman Instruments.
The middle and innermost rows could be used, but the extended ultracentrifugation times required for complete separation of top and bottom fractions as a result of the shorter radii precluded their use in high-throughput laboratory situations.
[beta]-Quantification depends on the physical separation of VLDL from other lipoproteins by ultracentrifugation, collection of the fractions, and finally reconstitution of the fractions back to the original specimen volume.
After ultracentrifugation, the top and bottom fractions were separated using a Beckman CentriTube Slicer (Fig.