Portable microfluidic device for extracting microbial DNA from soil

Abstract

A portable extraction device consisting of a microfluidic cartridge, a magnetic bead-based cleaning system and an electronic control unit, configured for automated extraction of microbial DNA from soil samples.

Description

Application area of ​​the invention:

[0001] The invention relates to biotechnology and microfluidic systems, in particular portable DNA extraction devices for microbial soil analysis using magnetic bead cleaning and smartphone integration for field applications. Background of the invention:

[0002] Extracting microbial DNA from soil samples is a crucial step in environmental monitoring, agricultural diagnostics, and forensic investigation. Conventional extraction methods are often time-consuming, laboratory-dependent, and require numerous manual steps such as centrifugation, pipetting, and the use of hazardous reagents. Soil, a complex matrix rich in humic acids, clay, and organic contaminants, impairs DNA isolation and purity, leading to inconsistent yields. Commercial kits require controlled laboratory conditions and skilled personnel, limiting their use in the field. Furthermore, the need for electrical infrastructure and heavy laboratory equipment restricts mobility and the ability to perform analyses on-site.Therefore, there is a growing need for a compact, automated, and contamination-free DNA extraction system that can process soil samples quickly and with minimal human intervention. The integration of microfluidics and magnetic bead-based purification enables efficient miniaturization and automation, while smartphone connectivity allows for user-friendly control and real-time data management in diverse field environments. Summary of the invention:

[0003] The present invention relates to a portable, handheld extraction device for the rapid and efficient isolation of microbial DNA from soil samples using microfluidics and magnetic particle technology. The system comprises a sterile, disposable microfluidic cartridge pre-filled with lyophilized reagents for lysis, washing, and elution. A soil chamber allows for sedimentation and filtration to remove coarse particles before the sample enters the microfluidic system. The device automates the individual steps of cell lysis, DNA binding to magnetic particles, washing to remove impurities, and elution of the purified DNA, which is suitable for subsequent molecular analysis.

[0004] The device integrates seamlessly with a smartphone app for wireless control, process monitoring, and data management. Users can initiate protocols, monitor extraction progress, and securely store results in the cloud via the smartphone interface—for example, to document the sample chain or for research purposes. The system is powered by a battery or solar energy, ensuring reliable operation even in remote locations. Its closed, self-contained design prevents contamination and guarantees reproducibility. The invention thus enables the extraction of high-quality DNA within 30 minutes and supports applications in precision agriculture, environmental microbiology, and forensic soil analysis. Detailed description:

[0005] The invention comprises a compact, portable housing with a removable microfluidic cartridge and integrated control electronics. The cartridge is made of biocompatible polymer materials and contains multiple microchannels, chambers, and valves for automated control of the reagent flow. The upper part includes a bottom chamber with fine-mesh filtration and a sedimentation zone for removing coarse soil particles and ensuring uniform sample loading. Downstream microchannels are connected to reagent reservoirs containing lyophilized lysis, wash, and elution buffers, which are rehydrated upon activation.

[0006] A micropump system controlled by an integrated microcontroller regulates the fluid flow through the cartridge. Magnetic particles functionalized with DNA-binding ligands are introduced into the lysis chamber, where the microorganisms are chemically and physically disrupted. The released nucleic acids selectively bind to the surface of the magnetic particles. Miniature magnets integrated into the housing fix the particles during the washing phase, allowing contaminants and inhibitors to be efficiently removed via the drain openings.

[0007] In the elution step, the bound DNA is released into a small buffer volume. This produces a purified extract ready for subsequent analyses such as PCR or sequencing. The purified DNA is collected in an elution chamber with an outlet for sample collection. The instrument's microcontroller synchronizes the fluidics, magnetic activation, and temperature control, ensuring optimal DNA yield.

[0008] The electronic control unit communicates wirelessly with a smartphone via Bluetooth or Wi-Fi. The accompanying mobile app allows the selection of extraction protocols, real-time visualization of the workflow, and automatic logging of metadata such as sample ID, location, and time. The extracted data is stored locally or uploaded to the cloud for remote access and analysis.

[0009] The housing is ergonomically designed with a comfortable grip and a shock-resistant casing, making it ideal for field use. The system is powered by a rechargeable lithium-ion battery and can be optionally equipped with a solar charging function to ensure operation even in remote or off-grid areas.

[0010] All fluid channels within the cartridge are single-use and sealed to prevent cross-contamination between samples. The microfluidic layout minimizes reagent consumption and reduces processing time while maximizing DNA yield. The modular architecture allows for future adaptations for other biological sample types, such as plant roots or sediments.

[0011] The automation and portability of the invention significantly reduce human error, improve reproducibility, and enable the extraction of microbial DNA directly in the field. This accelerates decision-making in agricultural diagnostics, environmental monitoring, and forensic applications, replacing cumbersome laboratory processes with an integrated, field-ready solution.

Claims

[1] A portable extraction device consisting of a microfluidic cartridge, a magnetic bead-based cleaning system and an electronic control unit, configured for automated extraction of microbial DNA from soil samples. [2] Device according to claim 1, wherein the microfluidic cartridge is preloaded with lyophilized reagents for lysis, washing and elution and comprises sedimentation and filtration units for removing soil particles. [3] Device according to claim 1, wherein the magnetic beads selectively bind nucleic acids and are separated from soil inhibitors by means of embedded magnets to obtain purified DNA suitable for subsequent molecular analyses. [4] Device according to claim 1, wherein a smartphone interface provides wireless control, monitoring and data storage functions and thus enables field use with rechargeable battery or solar power.