Microfluidics-based strategies for molecular diagnostics of infectious diseases

Abstract

Traditional diagnostic strategies for infectious disease detection require benchtop instruments that are inappropriate for point-of-care testing (POCT). Emerging microfluidics, a highly miniaturized, automatic, and integrated technology, are a potential substitute for traditional methods in performing rapid, low-cost, accurate, and on-site diagnoses. Molecular diagnostics are widely used in microfluidic devices as the most effective approaches for pathogen detection. This review summarizes the latest advances in microfluidics-based molecular diagnostics for infectious diseases from academic perspectives and industrial outlooks. First, we introduce the typical on-chip nucleic acid processes, including sample preprocessing, amplification, and signal read-out. Then, four categories of microfluidic platforms are compared with respect to features, merits, and demerits. We further discuss application of the digital assay in absolute nucleic acid quantification. Both the classic and recent microfluidics-based commercial molecular diagnostic devices are summarized as proof of the current market status. Finally, we propose future directions for microfluidics-based infectious disease diagnosis.

Microfluidic space coding for multiplexed nucleic acid detection via CRISPR-Cas12a and recombinase polymerase amplification

“…Microfluidics technology has been extensively used for molecular detection 39 – 42 . However, common microfluidic platforms have complicated fluidic networks, and often require valves, accessory pumps or other complex controlling systems 43 , 44 .…”

Integration of CRISPR/Cas12a and Multiplexed RPA for Fast Detection of Gene Doping

“…Recently, CRISPR/Cas-based systems have been extensively explored for in vitro diagnostics beyond their traditional applications in gene editing. − These functions could be achieved and expanded relying on the fact that Cas proteins exhibit cis - (cut the target sequences) and trans-cleavage (cut nontarget sequences) capabilities after the CRISPR-RNA (crRNA) recognizes the relevant target nucleic acid. − As next-generation biosensing platforms, CRISPR/Cas-based detection platforms have shown great specificity, sensitivity, flexibility, and simplicity. − To further improve the method sensitivity, amplification strategies such as PCR, LAMP, and recombinase polymerase amplification (RPA) were introduced into CRISPR/Cas systems. ,, As an isothermal amplification, RPA offers low cost, high speed, and ease of integration with portable instruments for on-site detection. , For example, many promising platforms have been established by combing CRISPR/Cas and RPA, such as SHERLOCK, DETECTR, and HOLMES …”

“…35,36,38 As an isothermal amplification, RPA offers low cost, high speed, and ease of integration with portable instruments for on-site detection. 39,40 For example, many promising platforms have been established by combing CRISPR/Cas and RPA, such as SHERLOCK, 29 DETECTR, 27 and HOLMES. 41 In this work, we propose a Cas12a-based GD detection platform (CasGDP) by combining the CRISPR/Cas12a system with multiplexed RPA for fast GD evaluation.…”

Merging microfluidics with luminescence immunoassays for urgent point-of-care diagnostics of COVID-19

“…It also requires large imaging equipment and specialized medical staff [ 15 ]. Nucleic acid assays, the gold standard for COVID-19 diagnosis, have played an irreplaceable role in epidemic prevention and control [ 9 , 16 ], which can detect patients in the window period and achieve early diagnosis accurately [ 17 ]. However, time-consuming amplification, requirements for professional equipment and operation limit their rapid detection [ 18 ].…”