A novel single nucleotide polymorphisms detection sensors based on magnetic nanoparticles array and dual-color single...

To fulfill the increasing need for large-scale genetic research, a high-throughput and automated SNPs genotyping method based on gold coated magnetic nanoparticles (GMNPs) array and dual-color single base extension has been designed. Biotinylated single base extension primer were captured onto the GMNPs coated with streptavidin. Dual-color fluorescence single base extension was employed as a tool for SNPs identification, and then a "bead array" was fabricated by spotting GMNPs with fluorophore on the glass slide. Using this platform, MTHFR gene C677T locus from 12 samples was genotyped. The results showed that all homozygous samples gave a signal/noise ratio over 30, and the fluorescent intensities ratios of heterozygote samples were around 1. With advantages to defeat the background subtract feature and read-out the fluorescence values of the GMNPs directly to determine their genotypes, without the necessary procedures for purification and complex reduction of PCR products, the application of this strategy to large-scale SNP studies will be simple, labor-saving, high sensitive and potential for automation.