For Genome Wide Association Studies (GWAS), variants present in the tested groups (patients and controls) can be identified using SNP arrays (often called bead arrays, high density arrays, microarrays or similar). Describe how these arrays can be used to characterise up to 1 million SNPs (Single Nucleotide Polymorphisms) in a single individual in a single experiment. Describe how the method works – that is, how the base present at each potential polymorphic site can be identified

what question is it

SNP Arrays for GWAS

layout

step,detials

details

Purpose
Technology Used
Probe Design
Sample Preparation

        Detection Method
        Readout
        Advantage

Purpose

Genotype up to 1 million SNPs in one experiment for GWAS.

Technology Used

Illumina Bead Arrays / High-Density SNP Arrays.

Probe Design

Short DNA oligos attached to beads; complementary to SNP site.

Sample Preparation

• Fragment and label patient DNA - Hybridize to array.

Detection Method

DNA synthesis incorporates fluorescent nucleotide; color identifies base.

Readout

Measure fluorescence for each SNP to determine genotype (AA, AG, GG, etc).

Advantage

High-throughput, cost-effective, widely used in GWA