A Novel Method for Preservation of Labile Lipid Samples at Ambient Temperature with Oxygen Absorber

Abstract

A novel method for preserving labile lipid samples at ambient temperature was developed with a commercially available oxygen absorber. In order to optimize the preservation conditions, the changes in the fatty acid composition of a triacylglycerol mixture during storage were determined by thermally assisted hydrolysis and methylation gas chromatography in the presence of trimethylsulfonium hydroxide. The polyunsaturated fatty acid (PUFA) components of the sample proved to degrade during preservation at room temperature through autoxidation induced by the trace amount of residual oxygen in a plastic bag for storage even coexisting with the oxygen absorber. On the other hand, once the lipid sample in the plastic bag with the oxygen absorber was subjected to 7 days “pretreatment” in a refrigerator at about 2°C, the PUFA components of the lipid sample in the bag were kept almost completely unchanged during further preservation at room temperature for at least four weeks. The observed results indicated that the residual oxygen in the plastic bag was sufficiently eliminated by the oxygen absorber during the “pretreatment” at about 2°C. Therefore, the labile lipid samples can be preserved at room temperature for a long time without deterioration by using oxygen absorber combined with the appropriate “pretreatment” storage in chilled conditions for a certain period. Moreover, reliable transportation of various biomaterial samples to a distant laboratory is able to be carried out conveniently at ambient temperature by this novel storing method without utilizing any special freezing system.