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The following article summarizes United States Patent Application No. US20180052155A1, titled ‘Assay Devices and Methods’ (filed 16 August 2016, published 22 February 2018). While lateral flow assays (LFAs) have revolutionized point-of-care diagnostics by enabling accurate, inexpensive, and rapid detection of biomarkers, they typically do not provide quantitative results. Hence, there is a significant need for quantitative assays at the point of care. This patent summary describes a novel method of chronometric biomarker quantitation via enzymatic degradation of a metastable gelatin-based biomatrix, principally suited for use in paper-based microfluidic devices (microPADs). This new quantitation mechanism was designed to meet the ASSURED criteria for point-of-care diagnostic devices laid forth by the World Health Organization and may ultimately provide increased access to healthcare, at a significantly reduced cost, around the world.

Nucleic acid (DNA/RNA) amplification technologies are indispensable for applications like disease diagnostics, forensics, epidemiology, evolutionary biology, vaccine development, and therapeutics. While polymerase chain reaction (PCR) has deeply penetrated the abovementioned fields and has been commercially successful, two major common disadvantages are exorbitant costs of associated equipment, which create concerning roadblocks in terms of affordability and accessibility. This work describes development of an inexpensive, portable, easy-to-use and deliverable-to-end-users, nucleic acid amplification technology for infectious disease diagnosis. The device uses loop-mediated isothermal amplification (LAMP) and cell phone-based fluorescence imaging to enable nucleic acid amplification and detection. A regular lab incubator and a custom-made low-cost imaging box are the only two additional equipment required for testing. Material cost for a 12-test zone device was $0.88, and cost of reagents per reaction was $0.43. First successful application of the device was demonstrated for tuberculosis diagnosis with clinical sensitivity of 100% and clinical specificity of 68.75% for testing of 30 clinical patient samples., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Nucleic acid amplification tests (NAATs) play a crucial role in the early diagnosis and prevention of various infectious diseases. Over the last decade, paper-based devices have garnered attention as low-cost devices for conducting NAATs at the point-of-care (POC). Sample preparation is a critical and one of the most cumbersome steps in a NAAT. We present a comprehensive review of paper-based nucleic acid (NA) sample preparation techniques that have been developed for various complex sample types. We project NAATs as a series of three-unit operations – lysis, purification, and amplification (lysis and purification together constitute the process of sample preparation). Any one or all three operations could be conducted in paper, resulting in multiple possible workflows. We categorize all published paper-based NA sample preparation strategies into one of these workflows, thus presenting a new way to rationally categorize the numerous paper-assisted NA sample preparation workflows. Towards the end, we present a perspective on progress in the field and conclude by enlising important gaps in the area to guide future research. [ABSTRACT FROM AUTHOR]