Acta bioquímica clínica latinoamericana
versión On-line ISSN 1851-6114
CARACCIOLO, Mirta Beatriz et al. Stability of specimens stored in primary tube: a study on 25 analytes of clinical chemistry. Acta bioquím. clín. latinoam. [online]. 2007, vol.41, n.3, pp. 353-358. ISSN 1851-6114.
The stability of 25 analytes during a seven-day storage in two different kinds of tubes was studied. PMMA (polimetilmetaacrilate) tubes contain a clotting activator (glass particles) and the other tubes contain a gel barrier. The aim was to determine the analytes' stability in both kinds of tubes and, as a consequence, to determine the optimal time for storage of the samples in the primary tube. The specimens were maintained at 4-8 ºC and analyzed in duplicate during seven days. The analytes' stability was determined by comparing the results obtained each day with those obtained on the first day. The significant change limits were based on the determination of the variation coefficient, on the biological variation and on statistically significant changes using a MANOVA test. Mean values of aldolasa, phosphate, glucose, lactic dehydrogenase, potassium and sodium stored in tubes with a clotting activator had statistical differences in comparison with the mean values of the same analytes stored with a gel barrier. Each laboratory should investigate the specific analytes' stability according to the collection device used.
Palabras clave : analytes' stability; clinical laboratory management; specimen's handling and processing.