Abstract: The present disclosure describes an adsorbent and exemplary protocols for extracting nucleic acids, such as DNA and RNA, from complex matrices, such as stool samples and water samples. The adsorbent is activated charcoal coated with a material such as polyvinylpyrrolidone, dextran, or coconut flours. The adsorbent may be used in microcentrifuge spin columns, where it may be present as a slurry in a storage solution. The sample may be prepared by vortexing in a buffer solution, centrifuging, adding a protease to the supernatant, and passing the supernatant through a microcentrifuge spin column containing coated activated charcoal. The key components, including buffer, protease, and spin columns, may be packaged in a kit.