Comparison and\nOptimization of Simple DNA Extraction\nMethods for LAMP-Based Point-of-Care Applications Employing Submillimeter\nSkin Biopsies

Loop-mediated isothermal amplification (LAMP) has gained\nparticular\nattention for point-of-care (POC) applications due to its advantages\nover traditional nucleic acid testing approaches. However, a prevailing\nlimitation of LAMP in POC applications is nucleic acid extraction\nfrom the sample prior to analysis. This is particularly true for complex\nsamples such as submillimeter skin biopsies where lysis and digestion\ninvolve intricate and lengthy procedures. The objective of this study\nwas to compare alternative methodologies against the spin-column laboratory\nstandard and evaluate them based on the World Health Organization\nASSURED criteria for POC testing. Four methodsmagnetic bead\nextraction, alkaline extraction, proteinase K-heat inactivation extraction,\nand boiling method extractionwere optimized utilizing porcine\nskin submillimeter punch biopsies and subsequently validated on human\nskin. Results show that both alkaline extraction and proteinase K-heat\ninactivation produce DNA yields equivalent to or higher than the spin-column\nmethod in porcine and human skin. When evaluated against the ASSURED\ncriteria, both methods demonstrated low complexity while being highly\nscalable and readily accessible. Overall, this comparative study established\na robust framework for selecting DNA extraction methods for submillimeter\nskin biopsies in POC applications. It also underscored the performance\nof the alkaline extraction method based on the ASSURED criteria, providing\nequivalent DNA yields to laboratory standards with reduced complexity\nand potential for cost-effective scalability.