Visual DNA microarray for detection of epidermal growth factor receptor (EGFR) gene mutations

Abstract

Objective. To develop a gold nanoparticle-based visual DNA microarray for simple and rapid screening of EGFR gene mutations. Methods. The DNA fragments contain epidermal growth factor receptor (EGFR) exons 18, 19, 20 and 21 were amplified by polymerase chain reaction (PCR) using biotin-modified primers. The amino-modified oligonucleotides were immobilized on glass surface, which were used as the capturing probes to bind the complement biotinylated target DNA. After the PCR product has been hybridized to the immobilized capture probe DNA on the glass slides, the Streptavidin-conjugated gold nanoparticles were introduced to the microarray via specific binding to 5ʹ-end biotin of the PCR products. The hybridization signal on array spots was enhanced and visualized by silver amplification. The EGFR mutation in 286 clinical samples from cancer patients were tested using the gold nanoparticle-based microarray and verified with Sanger DNA sequencing method. Results. A novel visual DNA microarray has been developed to detect EGFR mutations in tumor tissue specimens rapidly; its limit of detection (LOD) is up to 10⁻⁹ mol/L and distinguishes power to detect 5% gene mutation in the mixture samples. Conclusion. For its high specificity and sensitivity, simplicity, lower price and higher speed, the present visual mutation detecting technique has potential application in clinical fields.

Key Words::

• Receptor
• epidermal growth factor
• DNA microarrays
• nanoparticles
• pharmacogenetics

Acknowledgements

We are grateful to Hanjie Yu (Northwest University, Shannxi Province, China) for his excellent technical assistance.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.

This present work was supported by the Hainan province key project of science and technology (grant no. 080204).