RESUMO
We report the development of a time-resolved fluorometry-based immunoassay concept for the rapid measurement of three cardiac markers from whole blood, serum or plasma. Using a universal all-in-one (AIO) dry reagent concept, all the analyte specific reagents are built into a single microtire well, to which an identical assay protocol is applied. Addition of 5-20 microL sample (whole blood, serum or plasma) together with a universal buffer initiates the reaction, which is brought close to equilibrium in 15 min. After the wash step the Eu chelate-derived signal is measured directly from the dried surface. Application of this concept to the three cardiac markers illustrates its ability to provide rapid, highly sensitive and fully quantitative results over a large dynamic range with good reproducibility. Such a performance, especially when using whole blood specimens, is largely a consequence of the inherently fluorescent and stable Eu-chelate employed in the system. Correlation to commercial assays was excellent for all three analytes, as was between-sample matrix correlation using the AIO assays. The presented assay concept enabling a simple automation is particularly suited for point-of-care applications, where the performance characteristics are fully comparable to state-of-the-art central laboratory immunoassays.