Abstract
Specimens taken into Becton Dickinson lithium heparin Vacutainers with plasma separator were compared with specimens taken into ordinary Becton Dickinson lithium heparin Vacutainers. After overnight storage, results for sodium, potassium, phosphate, albumin, lactate dehydrogenase, alkaline phosphatase, and urate concentrations showed statistical differences. Only the difference observed in urate concentration is likely to affect clinical interpretation.