English
Background
Beckman Coulter’s DxI 9000 Access Immunoassay Analyzer is designed to achieve faster throughput, employ an enhanced chemiluminescent substrate (Lumi-Phos PRO), deliver shorter turnaround times, run more tests per reagent pack, and provide improved user workflows, when compared to the legacy Access UniCel DxI 800 Immunoassay System. The development has focused on system improvements, but the bottom-line goal is to ensure high-quality patient results. Assay data generated on the prototype analyzer demonstrates strong correlation and similar imprecision to the predicate platform, the Access 2 Immunoassay System. Highlighted here are select assays which are demonstrating improvements in sensitivity, like thyroid stimulating hormone (TSH), troponin (hsTnI), and procalcitonin (PCT).
Methods
A comprehensive assay menu has been characterized on the prototype analyzer, and all data are compared to the predicate platform performance. A panel of residual samples spanning the assay analytical measuring ranges and commercially available quality controls were tested across three reagent logs, two calibrator lots, multiple days of testing on three prototype analyzers and on three Access 2 systems. Accuracy, imprecision, and sensitivity were calculated and compared to the Access 2 predicate analyzer. Additional performance criteria have also been evaluated to understand assay linearity and dilution recovery.
Results
A subset of preliminary data for the Access TSH 3rd IS, Access hsTnI, and Access PCT assays generated on the prototype analyzer is presented here. Each of these assays exhibit a strong correlation between the Access 2 and DxI 9000 Analyzers, similar imprecision, and improved sensitivity as measured by limit of quantitation (LoQ). Further, both the TSH and PCT assays have more tests available from each individual reagent pack.
| Accuracy* | Sensitivity | |||
| DxI 9000 Analyzer | Access 2 Analyzer | DxI 9000 Analyzer | Access 2 Analyzer | |
| TSH | 5.9% | 6.6% | 0.002 µIU/mL‡ | 0.005 µIU/mL‡ |
| hsTnI | 6.2%† | 8.7%† | 0.76 pg/mL§ | 2.9 pg/mL§ |
| PCT | 4.3% | 6.4% | 0.003 ng/mL‖ | 0.005 ng/mL‖ |
*Passing Bablok slope
†Includes all samples above LoQ
‡TSH 200 tests/pack (20% CV LoQ calculated surrogate)
§hsTnI (10% CV LoQ calculated surrogate
‖PCT 100 tests/pack (20% CV LoQ calculated surrogate
Conclusions
Preliminary assay data generated on the DxI 9000 Access immunoassay analyzer prototype system demonstrates correlation to the Access 2 analyzer and enhanced performance. Additionally, characterization data demonstrate the opportunity to achieve improved sensitivity for assays including Access TSH 3rd IS, Access hsTnI, and Access PCT.
