Single base extension reaction-based surface enhanced Raman spectroscopy for DNA methylation assay

Area of Science:

• Biotechnology
• Molecular Biology
• Analytical Chemistry

Background:

• DNA methylation is crucial for genetic disease diagnosis, cancer progression, and pharmacogenomics.
• Existing DNA methylation assays are often laborious and time-consuming.
• There is a need for simple, highly sensitive DNA methylation detection methods.

Purpose of the Study:

• To develop a simple and highly sensitive DNA methylation assay.
• To utilize single base extension reaction and surface-enhanced Raman spectroscopy (SERS) for DNA methylation detection.
• To improve upon the sensitivity of existing DNA methylation assays.

Main Methods:

• A DNA methylation assay was developed using a gold nanoparticle-modified capture probe and single base extension reaction.
• Cyanine 5-deoxyribonucleoside triphosphate (cy5-dGTP) was used as a reporter molecule.
• Surface-enhanced Raman spectroscopy (SERS) was employed for signal detection, enhanced by additional gold nanoparticles.

Main Results:

• The assay demonstrated a detection limit of 3 pM for methylated DNA.
• It successfully distinguished methylation levels as low as 1% in the tumor suppressor gene CDKN2/p16/MTS1 (p16).
• The sensitivity was significantly higher (5 orders of magnitude) than colorimetric assays and (2 orders of magnitude) than microarray-based Ms-SNuPE.

Conclusions:

• The developed single base extension reaction-based SERS assay is simple, highly sensitive, and effective for DNA methylation detection.
• This method offers a significant improvement in sensitivity compared to existing techniques.
• The assay holds potential for detecting methylation status in tumor-linked genes for improved cancer diagnosis.