We perform whole genome genotyping assays, using Illumina’s Infinium assay technology. This allows large-scale interrogation of variations in the human genome, at very high call rates (routinely >99%).
The Infinium Assay protocol features single-tube sample preparation without PCR or ligation steps, significantly reducing sample handling errors. An enzymatic discrimination step provides high call rates and accuracy with unambigous locus selection. We can scale the Infinium assays by parallel handling of multiple samples at a time without compromising data quality. Infinium makes significant use of tag SNPs.
Tag SNPs are loci that can serve as proxies for many other SNPs (Daly et al., 2001). The use of tag SNPs greatly improves the power of association studies. Because tag SNP content has been employed on the HumanHap Genotyping BeadChips, more statistical power and genomic coverage can be achieved using fewer SNPs and statistical tests compared to other strategies using larger numbers of randomly chosen SNPs.
- HumanCytoSNP-12
- HumanOmniExpress
- HumanOmni1-Quad
- HumanOmni2.5-Quad
- ... please enquire for other BeadChips
Different types of BeadArrays have different minimum sample numbers. Please enquire while planning your project. To define the type of array required for your research contact us directly.
The Infinium Beadchips have several advantages:
- Average 15-30-fold redundancy for each SNP
- Call rates >99%
- Reproducibility >99.9%
- Most BeadArrays carry a "gene-centered" SNP selection (tag SNPs)
The Infinium technology is a multi step method to identify allele variations at many loci within the genome in parallel. It combines single tube sample preparation with virtualy unlimited assay multiplex scalability, dependent only on the number of features on the array.
- Whole Genome Amplification (WGA) of genomic DNA
- Fragmentation of DNA
- Precipitation and Resuspension
- Hybridization of Samples onto Beadchip
- Primer Extention of allele-specific Oligonucleotides (s. fig. 1)
- Scanning of BeadChip
- Data Analysis
- Figure 1: The principle of the Infinium technology relys on the hybridization of genomic DNA with 50mer oligonucleotides that are covently bound to beads. Each Bead carrys approx. 500,000 identical, locus-specific oligos. After hybridization an allele-specific primer extention reaction incorporates one of two coloured dyes into the extended oligo. During the final detection each bead is analyzed for its color content (100% color1, 100% color2, 50% mixture of both colors).
