Evaluation and Validation of the AusDiagnostics MT-Prep XL and AusDiagnostics Ultraplex-3 [SARS-CoV-2, Influenza and RSV 8-well Assay]
Ngoc Yen Kim Tran, Thuy Phan, Genevieve L. McKew, Steven Siarakas · ACTA SCIENTIFIC MICROBIOLOGY · 2022
A validation study was conducted on the AusDiagnostics MT-Prep XL and AusDiagnostics SARS-CoV-2, Influenza and RSV 8-well assay performed on the AusDiagnostics Ultraplex 3 system.The Cycle threshold (Ct) of clinical patient samples spiked with a positive control, was compared to the reference laboratory standard, AusDiagnostics MT-Prep and Highplex System.The analytical performance was evaluated to establish the limit of detection (LOD), precision and agreement.There is an average difference in Ct of -0.883 and 0.078 between the nucleic extractors and MT-PCR systems, respectively.There was strong correlation (R-value ranging from 0.78 -0.91 for all gene targets) between the AusDiagnostics Ultraplex-3 and Highplex.Bland Altman analysis demonstrated the overall differences between the assays are within the limits of agreement (LoA).The AusDiagnostics MT-Prep XL has a processing time of 1.04 minute/sample and AusDiagnostics Ultraplex 3, 1.93 minute/sample, demonstrating a higher efficiency rate compared to the reference standard.RSV and SARS-CoV-2 detection in clinical samples were compared to the AusDiagnostics Highplex system as a reference standard.The assay demonstrated 99.10% overall agreement, with a PPA 100% and NPA of 99%.Kappa statistics of 0.95 (p < 0.05) suggests excellent agreement level between the two platforms.Moreover, precision study was conducted to observe the intra-run and inter-run assay variability.The calculated average Ct observed in all targets is 1.063% and 1.682%, respectively.The CV% is <2% suggesting high precision, low variability, and dispersion in data points.The commercialized AusDiagnostics MT-Prep XL and Ultraplex 3 is a viable platform, fit for purpose in detecting the SARS-CoV-2, Influenza A, Influenza B and RSV respiratory viruses.It's high efficiency rate and 96-sample capacity enhances laboratory throughput and enables faster time to result in comparison to the current reference standard.