Liquid biopsy genotyping by a simple lateral flow strip assay with visual detection

Area of Science:

• Biotechnology
• Molecular Diagnostics
• Oncology

Background:

• Liquid biopsy offers real-time tumor genome monitoring for cancer diagnosis and treatment decisions.
• Analysis of circulating tumor DNA (ctDNA) is a key component of liquid biopsy but faces challenges due to low concentration and fragmentation.
• Existing ctDNA analysis methods are often complex, time-consuming, and expensive for routine diagnostics.

Purpose of the Study:

• To develop a novel, simple, and rapid lateral flow strip assay for the visual detection of ctDNA mutations.
• To utilize gold nanoparticles as reporters for enhanced signal detection in the lateral flow assay.
• To demonstrate the assay's utility for detecting specific KRAS gene mutations relevant to colorectal cancer (CRC).

Main Methods:

• Development of a lateral flow strip assay for visual detection of ctDNA mutations.
• Utilized gold nanoparticles as reporters for the DNA biosensor.
• Selected common single-point KRAS gene mutations (G12D/A/V) and wild-type KRAS for method development and validation.
• Tested the assay on synthetic DNA, cancer cell lines, and cfDNA from healthy individuals and CRC patients.

Main Results:

• Successfully developed a lateral flow strip assay for visual mutational analysis of ctDNA.
• Demonstrated the detection of three KRAS mutations (G12D/A/V) and wild-type KRAS in various samples.
• The assay provides rapid (∼10 min) results with high detectability, specificity, and reproducibility.
• The method is cost-effective and does not require specialized instrumentation.

Conclusions:

• The proposed lateral flow assay offers a simple, rapid, and visual method for ctDNA genotyping.
• This assay serves as a cost-effective and portable alternative for liquid biopsy applications.
• The technology has the potential to be a universal device for rapid cancer diagnostics.