Synergetic performance of isothermal amplification techniques and lateral flow approach for nucleic acid diagnostics

The advancement in developing sensitive, rapid, and specific sensing tools is crucial in diagnostics and biotechnological applications. Although various isothermal amplification approaches exist for the detection and identification of nucleic acids, post-amplicon analysis is still based on traditional methods such as gel electrophoresis, colorimetry, turbidity, which could be non-specific and inconvenient. Thus, this review will first elaborate various isothermal amplification techniques (principle, merits, and demerits) and their potentials when combined with lateral flow approach for point-of-care nucleic acid diagnostics. Different methods for monitoring carryover contamination resulting from amplification product contamination will be discussed. Then, we will present recent advances in diagnostics with both target pre-amplification and CRISPR-Cas systems, which exhibit collateral cleavage of target nucleic acid and a reporter single strand nucleic acid within the vicinity. When the reporter is fluorophore-labeled, it provides a detectable signal by fluorescence or lateral flow biosensors. Lastly, we will discuss how CRISPR-Cas system based diagnostics could be more effective, affordable and portable for on-site detection.