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Updated: Jun 26, 2025

Efficient SARS-CoV-2 Quantitative Reverse Transcriptase PCR Saliva Diagnostic Strategy utilizing Open-Source Pipetting Robots
Published on: February 11, 2022
Cost-effective in-house COVID-19 reverse transcription-polymerase chain reaction testing with yeast-derived Taq
Mahmoud Zhra1, Aljohara Al Saud1, Maha Alzayer1
1Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
Background:
Despite the decline of the COVID-19 pandemic, there continues to be a persistent requirement for reliable testing methods that can be adapted to future outbreaks and areas with limited resources. While the standard approach of using reverse transcription-polymerase chain reaction (RT-PCR) with Taq polymerase is effective, it faces challenges such as limited access to high-quality enzymes and the presence of bacterial DNA contamination in commercial kits, which can impact the accuracy of test results.
Methods:
This study investigates the production of recombinant Taq polymerase in yeast cells and assesses its crude lysate in a multiplex RT-PCR assay for detecting the SARS-CoV-2 RNA-dependent RNA polymerase (RdRP) and N genes, with human Ribonuclease P serving as an internal control.
Results:
The unpurified yeast Taq polymerase demonstrates sensitivity comparable to commercially purified bacterial Taq polymerase and unpurified bacterial counterparts in detecting the RdRP and N genes. It exhibits the highest specificity, with 100% accuracy, for the N gene. The specificity for the RdRP gene closely aligns with that of commercially purified bacterial Taq polymerase and unpurified bacterial Taq polymerase.
Conclusions:
The use of unpurified recombinant yeast Taq polymerase shows promise as a cost-effective approach for conducting in-house COVID-19 RT-PCR testing. By eliminating the need for chromatography purification steps, the production of RT-PCR kits can be streamlined, potentially improving accessibility and scalability, especially in resource-limited settings and future pandemics.

