Surface modification of Beckman Ultra-Clear centrifuge tubes for density gradient centrifugation of lipoproteins.

A simple procedure for coating the interior surface of Beckman Ultra-Clear centrifuge tubes with polyvinyl alcohol is described. The coated tubes are wettable and allow salt solutions to gravity-feed down their sides. This modification of the tubes permits the performance of previously developed density gradient and uniform density ultracentrifugation procedures for lipoprotein fractionation.