Gold Nanoparticles Replaces Gel Electrophoresis in PCR Product Detection and SNP Genotyping
Research Summary: We developed a rapid, low-cost gold nanoparticle-based colorimetric assay for SNP genotyping that visually detects PCR amplification without agarose gel electrophoresis or toxic dyes.
Researcher Spotlight
Surya Kant Verma completed his Ph.D. in Animal Biochemistry, with research focused on molecular biology, molecular genetics, SNP genotyping, nanobiotechnology, and functional genomics in livestock species.
Linkedin: www.linkedin.com/in/surya-kant-verma-1346bb201
Instagram: https://www.instagram.com/surya_skv08bt/
Lab: Dr. Suneel Kumar Onteru, ICAR–National Dairy Research Institute, Karnal, India
What was the core problem you aimed to solve with this research?
Conventional allele-specific PCR-based SNP genotyping methods using agarose gel electrophoresis are expensive, time-consuming, and depend on toxic chemicals like ethidium bromide and specialized instruments. We wanted to create a safer, affordable, and easy-to-use alternative suitable for resource-limited laboratories.
How did you go about solving this problem?
We combined allele-specific PCR products with citrate-capped gold nanoparticles (AuNPs) solution at a certain volume ratio for visual detection of PCR amplification. In this assay, amplified PCR products protected AuNPs from aggregation and retained their pink/red color, whereas non-amplified products caused aggregation and turned the solution blue. This enabled naked-eye visualization of PCR amplification without electrophoresis.
“Our study demonstrates a simple and affordable visual detection method for PCR amplification and SNP genotyping suitable for point-of-care applications.” – Dr. Suneel Kumar Onteru
How would you explain your research outcomes (Key findings) to the non-scientific community?
We created a simple and rapid test where DNA amplification can be identified just by observing color changes. If the test remains pink, the DNA target is present in an amplified state; if it turns blue, the target amplification is absent. This removes the need for expensive machines, harmful chemicals and time to perform electrophoresis.
What are the potential implications of your findings for the field and society?
This method can make genetic testing more affordable, safer, and accessible, especially in low-resource laboratories and point-of-care settings. It may help researchers and clinicians perform rapid SNP genotyping without sophisticated equipment, such as electrophoresis apparatus.
What was the exciting moment during your research?
The most exciting moment was when we first observed a clear visual color difference between amplified and non-amplified PCR products using gold nanoparticles, confirming that electrophoresis-free genotyping was possible.
Paper reference: Verma, S.K., Kumar, L.K., Mitra, M.D., Kumar, J., Singh, P., Mohiddin, R., Nayan, V., Singh, D. & Onteru, S.K. (2026). Gold nanoparticle-based electrophoresis-free colorimetric detection method for allele-specific PCR-SNP genotyping. Analytical Biochemistry, 716, 116142. https://doi.org/10.1016/j.ab.2026.116142
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