Twinstrand Biosciences Inc, a company out of University of Washington is developing duplex sequencing to detect ultra-rare variants that are invisible otherwise for oncology and forensic discovery. Duplex sequencing uses adapters to tag both strands of DNA to identify and compare sequences derived from amplified copies of each strand. Errors are then removed from PCR duplicates and tags are matched to complementary tags. Duplex sequencing is able to detect mutations, and apply that knowledge to a variety of subjects involving oncology, infectious diseases, organ transplants, genetic health, and forensics.