Analytical performance of Elecsys 2010--a multicentre evaluation

The analytical performance of Elecsys 2010 has been assessed in a multicentre evaluation, which involved twelve laboratories from eight countries worldwide. Eleven alanytes (TSH, T4, FT4, T3, FT3, T-up, TNT, CK-MB, HCG, CEA and PSA) were tested using a protocol related to the ECCLS guidelines and the Standard Operating Procedures of the manufacturer. The evaluation was supported by a "Computer Aided Evaluation" (CAEv) program system and telecommunications. Within-run and between-day imprecision for the various analytes with 3% CV and 3 to 8% CV, resp. was comparable to homogeneous immunoassays e.g. for specific proteins on clinical chemistry analysers. The functional sensitivity for TSH, TNT and PSA was met by low concentrations: < 0.02 microIU/ml TSH, < 0.05 ng/ml TNT and < 0.07 ng/ml PSA. TSH is an assay of the third generation according to the recommendation of Spencer. The measured lower detection limit was less or equal to the manufacturer's specifications with the exception of the PSA assay. Drift effects (over eight hours) and signal carry-over effects were not observed. A high-dose hook effect became relevant for concentrations higher than 430,000 IU/HCG--an assay with a dynamic range of 10,000 IU/I. The Elecsys assays showed a high dynamic range and rarely necessary predilutions could be performed by the Elecsys instrument using the Elecsys multidiluent. Endogenous interferences were not observed. Calibration stability was confirmed for one week and data indicated that it could be extended at least for three weeks. The quality assurance experiment showed a good transferability of the results between the participating laboratories. The assigned values of two interlaboratory survey materials were found for most of the analytes within a deviation of +/- 10%. Higher deviations could be explained by differences in standardization and methods. The Elecsys 2010 system offers a high analytical sensitivity in combination with relatively low sample volumes and short measuring times (< or = 18 minutes); a high dynamic measuring range reduces the number of reruns and makes the work-flow more convenient. The electrochemiluninescence technology of Elecsys 2010 shows advantages in system performance without having any drawbacks compared to existing technologies.