Evaluation of heat-sealed ultracentrifuge tubes in the isolation of plasma lipoproteins.

An initial step in the measurement of the concentration of lipids in plasma lipoproteins by the Lipid Research Centers' protocol is the separation of very low density lipoproteins from low density and high density lipoproteins by ultracentrifugation. We compared the performance of heat-sealed centrifuge tubes to the conventionally capped centrifuge tubes required by the protocol in terms of the separation and recovery of cholesterol and triglyceride. No significant differences in either parameter were found, however the heat-sealed tube required much less time to prepare and eliminated the need for periodic replacement of relatively expensive cap parts. We recommend the use of heat-sealed tubes for the routine separation of plasma lipoproteins.