A-247 Performance and Compatibility Assessment of Serially Diluted Microbix QAPTM Controls with Seegene NovaplexTM Assays
Authors: Cheon D , Pineda S , Tran T 
Published: October 2024

Abstract

Background
Choosing high-quality external (third-party) controls like Microbix QAPTM PROCEEDxTM Controls and REDxTM Controls is crucial during test development, validation of Laboratory Developed Tests (LDTs), performance verification, proficiency testing, instrument qualifications, operator training and R&D testing. Laboratories may prefer to include multiple positive controls at varying concentrations to achieve reliable performance across a broad range of detection concentrations. In this study, we assess the performance and compatibility of Microbix QAPTM PROCEEDxTM liquid Controls and REDxTM swabs with Seegene’s real time qPCR assays that utilize TOCE and MuDTTM technologies. TOCE and MuDTTM technologies achieve multiple reads in a single channel and are the backbone of Seegene’s wide coverage panel assays.

Methods
The controls below were reconstituted and/or diluted in Copan UTM and extracted on the Seegene STARlet liquid handler using Seegene’s STARmag Universal extraction kit. After extraction, PCR was run on the Bio-Rad CFX 96 Opus Dx and analyzed using the Seegene Viewer software.

Results
Microbix QAPsTM liquid formulations were tested at various dilutions from stock up to 1/2048 with N=5per dilution. The VP-13-01 Flu A control was detected up to a concentration of1/2048 and at this dilution had Ct values of 30 + 0.3 for the Novaplex Respiratory Panel 1A (RP1A) Assay, 28.6 + 0.3 cycles for the Seegene SARS-CoV-2/FluA/FluB/RSV (Quad) Assay, and 27.9 + 0.3 for the Respiratory Virus Master (RVM) Assay. The Microbix VP-14-01 Flu B control was detected up to 1/2048 with Ct values of 34.3 + 0.3 for the RP1A Assay, 30 + 0.5 for the Quad Assay, and 30.3 + 0.3 for the RVM Assay. The VP-07-01 RSV A control was also detected at a 1/2048 dilution with Ct values of 32.7 + 0.3 for RP1A, 30.6 + 0.6 for Quad Assay, and 29.2 + 0.4 for RVM. The VP-61-01 Trichomonas vaginalis (TV) control was detected up to a dilution of 1/128 with a Ct value of 37.3 + 0.4 when tested with the Seegene Sexually Transmitted Infection Essential (STI) Assay. The VP-02-M1 HSV1 control was detected up to a dilution of 1/128 with a Ct value of 31.3 + 0.7 for the Seegene Genital Ulcer (GU) Assay. The VP-23-M1 HSV2 control was detected p to a dilution of 1/128 with a Ct value of 31.9 + 0.5 for the GU Assay. Microbix also makes a dry swab formulation product line that we tested in 3mL of UTM. Of these we tested the RED-S-10-M1 swab covering the SARS-CoV-2, Flu A, Flu B, and RSV controls. The VP-S-12-M5 swab covering the Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and TV controls. We also tested the VP-S-03-M1 swab covering HSV1, HSV2, VZV and syphilis controls. When tested with various assays all swabs were detected at the stock formulation.

Conclusions
Microbix QAPsTM are inactivated whole-organism controls, mimicking patient samples, and meet the stringent demand for quality or performance assessments. Their compatibility with Seegene’s Assays over a range of dilutions and formulations makes them ideal for ensuring reliable detection across multiple diagnostic needs.