A novel automated assay with dual-color hybridization for single-nucleotide polymorphisms genotyping on gold magnetic nanoparticle array

A high-throughput and cost-effective single-nucleotide polymorphism (SNP) genotyping method based on a gold magnetic nanoparticle (GMNP) array with dual-color hybridization has been designed. Biotinylated single-strand polymerase chain reaction (PCR) products containing the SNP locus were captured by the GMNPs that were coated with streptavidin. The GMNP array was fabricated by immobilizing single-stranded DNA (ssDNA)-GMNP complexes onto a glass slide using a magnetic field, and SNPs were identified with dual-color fluorescence hybridization. Three different SNP loci from 24 samples were genotyped successfully using this platform. This procedure allows the user to directly analyze the bead fluorescence to determine the SNP genotype, and it eliminates the need for background subtraction for signal determination. This method also bypasses tedious PCR purification and concentration procedures, and it facilitates large-scale SNP studies by using a method that is highly sensitive, simple, labor-saving, and potentially automatable.