Scaled-Up Paper Dipsticks for Nucleic Acid Extraction from Soil Samples

Nucleic acid extraction from soil samples holds paramount importance in various scientific domains, particularly in environmental microbiology, molecular ecology, and agricultural sciences. This process serves as a foundational step for numerous downstream applications, enabling a deeper understanding of soil microbial communities and their functions. Paper-based rapid nucleic acid extraction is the most cost-effective and easily accessible method available for nucleic acid extraction. In contrast to previous attempts at developing paper-based dipsticks for nucleic acid extraction, which could only analyze samples of volume < 10 μL, we report a method that enables the extraction of nucleic acids from samples 50 times larger in volume (50–650 μL). Our new design involves the use of paper-based dipsticks with corrugated edges and a pointed tip, which can be further joined together at the handle to create stacked dipsticks, thereby increasing the surface area of the dipstick in contact with the sample, and the volume of the sample from which nucleic acid can be extracted. The extracted DNA has later been quantified using a benchtop UV–vis spectroscopy-based DNA quantification device to calculate the extraction efficiency (%) of the samples under study. The application of our paper-based nucleic acid extraction dipstick has been demonstrated by conducting controlled experiments to extract nucleic acid from garden soil samples. The highest extraction yield (%) obtained was found to be approximately 52% for a soil sample spiked with DNA with a concentration of 1000 nM using a 10-stack dipstick.