A method for long term stabilisation of long chain polyunsaturated fatty acids in dried blood spots and its clinical application.

Conventional assays of omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) status in humans involve venous blood collection and expensive, multi-step processes that limit their usefulness as screening tools. This study aimed to develop a capillary dried blood spot (DBS) system capable of protecting n-3 LCPUFA from oxidation for up to 2 months at room temperature (20-25°C). We demonstrated that a DBS system comprising both an antioxidant and chelating agent on silica-gel coated paper prevented any significant change in the n-3 LCPUFA profile after 2 months. Our DBS assay was then tested in fifty subjects, and this demonstrated the presence of strong and significant correlations between the results obtained from the DBS system and those obtained from conventional measures for all fatty acids, in particular the n-3 LCPUFA EPA and DHA (r>0.96, P<0.0001). This study therefore validates our DBS system as a reliable method for the assessment of n-3 LCPUFA status in humans.