Sulfur atom modification on thymine improves the specificity and sensitivity of DNA polymerization and detection.

Abstract

Although accurate base-pairing ensures specificity of molecular recognition, DNA polymerization and DNA amplification, there are many non-specific pairings that arise from mismatched pairs, such as the T/G wobble pair. We have found that by using 2-S-TTP (STTP), we can minimize T/G mismatch, improve the DNA polymerization specificity and enhance the detection sensitivity (up to 20 fold), without significantly compromising the polymerization efficiency (the extension rate ratio of TTP vs.STTP is 1.08). With the STTP strategy, DNA polymerization is more specific and allows the detection of pathogens (such as COVID-19) in single digits (up to 5 copies), which is not possible with conventional RT-PCR. We have discovered that STTP can generally promote much higher specificity and sensitivity in DNA polymerization and nucleic acid detection than canonical TTP.