Access hsTnI

Access hsTnI is a chemiluminescent immunoassay that quantitatively measures cardiac troponin I (cTnI) levels in human serum and plasma samples using automated analyzers. It is intended to aid in diagnosing myocardial infarction (MI) and employs a sandwich assay principle with paramagnetic particles and alkaline phosphatase detection.

The candidate assay uses identical chemistry, sandwich immunoassay principle, sample types (serum and lithium heparin plasma), measuring range (2.0–27,027 pg/mL), precision specifications, reference limits, and reagent formulation as the predicate. The key difference is the instrument platform: the candidate runs on the DxC 500i Clinical Analyzer, while the predicate runs on the Access 2 Immunoassay System.

CLSI EP05-A3 (precision performance), CLSI EP06-2nd Edition (linearity), CLSI EP17-A2 (detection capability), CLSI EP09-ED3 (method comparison and bias estimation), and FDA's Assay Migration Studies guidance for In-Vitro Diagnostics Devices (April 2013).

Platform equivalency was demonstrated through method comparison studies across multiple instrument pairs and test sites showing slope and correlation meeting acceptance criteria (slope 1.00 ± 0.10, r ≥ 0.90). Analytical performance (imprecision, linearity, and detection limits) on the DxC 500i met the same predicate specifications. Clinical samples spanning the full measuring range produced equivalent results between platforms, confirming the assay performs identically despite the instrument change.