A site-specific DNA methylation biosensor for both visual and magnetic determination based on lateral flow assay

Area of Science:

• Biotechnology
• Molecular Biology
• Nanotechnology

Background:

• Abnormal DNA methylation is a key driver of tumorigenesis.
• Accurate detection of cancer-specific gene methylation is crucial for precision medicine.
• Existing methods for methylation detection can be complex and require specialized equipment.

Purpose of the Study:

• To develop a portable, rapid, and sensitive biosensor for site-specific DNA methylation detection.
• To enable both visual and magnetic determination of methylation status.
• To facilitate the popularization of precision medicine through accessible diagnostic tools.

Main Methods:

• A lateral flow assay-based biosensor utilizing gold magnetic nanoparticles (GMNPs).
• PCR amplification with digoxin- and biotin-labeled primers for amplicon recognition and capture by GMNPs.
• Visual detection via GMNP optical properties and magnetic detection using a magnetometer.
• Development of tailor-made primer sets for distinguishing low percentages of methylated variants.

Main Results:

• The biosensor allows for naked-eye visual interpretation and magnetometer-based recording of methylation status.
• High sensitivity achieved, detecting as low as 0.01 pg of methylated variants.
• Accurate distinction of 0.1% methylated variants in the presence of unmethylated background.
• Successful determination of miR-34a promoter methylation in cell lines and clinical samples.

Conclusions:

• The developed biosensor offers a versatile platform for DNA methylation analysis.
• Its portability, speed, and sensitivity make it suitable for clinical applications.
• The biosensor shows significant potential for cancer diagnosis and prognosis, particularly for genes like miR-34a.