Point-of-care plant DNA detection via dipstik-seq technology

Overview

DipStik-Seq is a point-of-care nucleic acid detection technology developed by ama biotech Inc, now being adapted for plant DNA testing. The platform combines a simple, shelf-stable silica dipstick isolation method with a non-enzymatic colorimetric DNA strand displacement assay, eliminating the need for laboratory infrastructure. Originally created for at-home STD testing using menstrual samples, the technology is well-suited for any application where cell-free DNA is abundant, including agricultural pathogen detection, crop verification, and plant biosecurity screening. The plant adaptation requires only a single lysis step to liberate DNA from plant tissue before dipstick capture and colorimetric detection.

Technical specifications

Key features:

• Silica dipstick isolation: A portable dipstick selectively binds nucleic acids from crude biosamples, replacing centrifuge-based purification with a field-deployable workflow
• Non-enzymatic colorimetric readout: Shelf-stable DNA strand displacement cascades detect specific genetic sequences without requiring enzymes, cold storage, or specialized equipment
• Single-tube lysis step: Plant material is processed using a pestle and lysis solution (with enzyme and enzyme-free variants in development) to release DNA for capture
• Bioinformatic target design: Optimal detection sequences are identified based on proximity to cutsites, improving assay sensitivity for SNPs and specific genes
• Operator-independent design: The dipstick modality is robust to user variability, making it suitable for non-laboratory environments

How it works: A plant tissue sample is disrupted in a single tube using a lysis solution, releasing DNA into the crude lysate. The DipStik binds nucleic acids selectively from this mixture, which are then eluted and tested for unique genetic sequences via a colorimetric strand displacement cascade. Alternative detection methods, including field-deployable PCR, are being explored for non-consumer-facing applications.

Technology readiness level

The core DipStik isolation and colorimetric detection technology has been validated with human cell-free DNA samples, demonstrating successful capture and detection of a ~15-nucleotide target sequence by both DNA strand displacement assay and PCR. Purity assessments by spectrophotometry confirmed a discrete absorbance peak at 260 nm, though some residual signal around 400–430 nm suggests minor contaminants. An initial proof-of-concept with moth DNA in a teaching lab demonstrated that a single lysis step enables plant-tissue DNA capture. The plant-specific adaptation is in early-stage development, with a planned 3–6 month refinement phase covering lysis optimization, dipstick tuning, and scalability, followed by a 4–8 month phase focused on bioinformatic target selection and assay signal optimization. The technology is at a technology readiness level appropriate for collaborative development toward field validation.