A stabilizing agent, PCA/DTPA, improves plasma storage life for the chromsystems vitamin C assay up to six months

Abstract

The commonly used Chromsystems vitamin C (ascorbate) assay (Munich, Germany) has a sample storage life of five days at –20°C. Stabilizing agents have been successfully used to increase longevity; however, their suitability with this commercial assay is unclear. We investigated the compatibility of a stabilizing agent, perchloric acid/diethylenetriaminepentaacetic acid (PCA/DTPA), with the Chromsystems assay. Plasma was stored at –80°C, with or without PCA/DTPA. Storage up to six months was assessed through baseline and repeat analyses, stability was assessed by comparing paired non-stabilized and PCA/ DTPA-stabilized plasma, and performance was assessed using allowable performance specificat..