Exploring the Impact of Primer–Template Mismatches on PCR Performance of DNA Polymerases Varying in Proofreading Activity

Abstract

Polymerase chain reaction (PCR) is a widely used technique in gene expression analysis, diagnostics, and various molecular biology applications. However, the accuracy and sensitivity of PCR can be compromised by primer–template mismatches, potentially leading to erroneous results. In this study, we strategically designed 111 primer–template combinations with varying numbers, types, and locations of mismatches to meticulously assess their impact on qPCR performance while two distinctly different types of DNA polymerases were used. Notably, when a single-nucleotide mismatch occurred at the 3’ end of the primer, we observed significant decreases in the analytical sensitivity (0–4%) with Invitrogen™ Platinum™ Taq DNA Polymerase High Fidelity, while the analytical sensitivity remained unchanged with Takara Ex Taq Hot Start Version DNA Polymerase. Leveraging these findings, we designed a highly specific PCR to amplify Babesia while effectively avoiding the genetically close Theileria. Through elucidating the critical interplay between types of DNA polymerases and primer–template mismatches, this research provides valuable insights for improving PCR accuracy and performance. These findings have important implications for researchers aiming to achieve robust qPCR results in various molecular biology applications.