Extended storage of whole blood with 3-deazaadenosine for homocysteine assay

Abstract

Background: To assess the effectiveness of using 3-deazaadenosine (3DAA) to maintain plasma homocysteine concentrations (tHCy) in whole blood samples. Methods: Blood was obtained from five volunteers and samples were maintained at room temperature, in cold packs or in a fridge (0-4°C) with and without 3DAA. At time points ranging from 6 to 168 h, samples were processed and analysed for tHCy using the Abbott IMx system. Results: There was a mean increase in tHCy of 29.4% at 6 h increasing to 242.6% after 168 h in whole blood kept at room temperature. There was no significant change in tHCy for 48 h when stored in cold packs, and for 72 h when stored in the fridge. The addition of 3DAA had a significant preservative effect ( P<0.001), maintaining tHCy to 48 h in whole blood at room temperature, 120 h in the fridge and 96 h in cool packs. There was no statistical difference in results obtained from samples containing preservative and controls when using the Abbott IMx system. Conclusion: 3DAA is an effective preservative of tHCy in whole blood, particularly in samples maintained at 0-4°C.