Introduction
The Illumina® Infinium EX Assay™ provides streamlined sample preparation and high-level multiplexing. The assay uses improved pharmacogenomics (PGx) target preparation with core Infinium I and Infinium II probe designs and a dual-color channel approach to enable the DNA analysis of several million SNPs and copy number variation (CNV) markers per sample.
The Infinium EX Assay accomplishes multiplexing by using a new PGx target preparation process that combines whole genome amplification and targeted gene amplification with direct, array-based capture and enzymatic scoring of the
SNP loci. PGx target preparation enables accurate calls for genes impacted by pseudogene interference. Locus discrimination or CNV determination comes from a combination of high bead type representation per feature, sequence-specific hybridization capture, and
array-based, single-base primer extension. With the Infinium I probe design, the 3' end of the primer overlaps with
the SNP site. If there is a perfect match, extension occurs and a signal is
generated. If there is a mismatch, extension does not occur and no signal is
generated. With the Infinium II probe
design, the 3' end of the primer is positioned directly adjacent to the SNP
site, or if a nonpolymorphic probe, directly adjacent to the nonpolymorphic site.
Allele-specific, single-base extension of the primer incorporates a biotin nucleotide or a dinitrophenyl labeled nucleotide. C and G nucleotides are biotin labeled. A and T nucleotides are dinitrophenyl labeled. Signal amplification of the incorporated label further improves the overall signal-to-noise ratio of the assay.
The Infinium EX Assay offers the following features:
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High-level multiplexing. |
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High call rate and accuracy. |
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Unlimited genomewide marker selection. |
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Minimal risk of carryover contamination. |
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Compatibility with Illumina iScan System. |
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Multiple-sample BeadChip format. |
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Complete end-to-end automation solution. |
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Improved reagent chemistry. |
