Metrological characteristics of the A25® analyzer

A25® from BioSystems is a random-access analyser useful for clinical chemistry routine assays in different kinds of biological samples. Some of its metrological characteristics were evaluated in this study in 10 methods for enzyme measurement and 16 methods for substrates. Metrological characteristics were: within- and between-run imprecision, detection limit, critical limit, bias, sample and reagent carry-over, and sample on-board stability. Both within-run and between-run imprecision for almost all assays met the established criteria with a few exceptions. Coefficients of variation for total imprecision were below 5 % with few exceptions. Results for detection limit, critical limit and bias were considered acceptable. No carry-over in sample pipetting system was observed, and, in reagents, only for some combinations: alanine-aminotransferase/L-lactate-dehydrogenase, aspartate-aminotransferase/L-lactate-dehydrogenase and glucose/ phosphate. A25® analyser has proved to be a versatile instrument, easy to handle and especially useful for small- to medium-sized laboratories or emergency laboratories.