For the T1DGC study, the 4,000 T1D case and 2,500 control DNA samples were selected based on no prior use in a prior genome wide association study and migration as a high molecular weight band of genomic DNA, ∼23 kb, by electrophoresis on a 0.75% agarose gel. All DNA samples were extracted using a chloroform-based method and quantified in triplicate using Picogreen®. Once selected, the case and control DNA were randomized by columns into a 96 well plate format.
