The Infinium HumanHap550-Duo BeadChip provides the same content as the HumanHap550 BeadChip in a dual-sample format, resulting in higher throughput and lower cost per sample. The HumanHap550-Duo contains more than 550,000 SNPs, selected based on a novel tag SNP approach. This approach to content selection allows investigators to accelerate their research by maximizing study power with fewer samples.