Twinstrand Biosciences Inc.

TwinStrand Biosciences Inc. is a privately held biotechnology company headquartered in Seattle, Washington, founded in 2015. The company is venture-backed, having raised a total of $84 million in funding. Employee counts have fluctuated, with reports of 64 employees as of 2023 and 13 as of March 2026.

TwinStrand Biosciences develops and commercializes its proprietary Duplex Sequencing® technology, an ultra-high accuracy, error-corrected next-generation sequencing (ecNGS) method. This technology significantly reduces sequencing error rates, enabling the detection of ultra-low frequency genomic variants that are often undetectable by conventional methods. The company offers products such as AML Assays for residual cancer detection and formerly offered Mutagenesis Assays for genetic toxicology, along with custom services. In July 2024, TwinStrand Biosciences licensed its patent estate in cell-free nucleic acid sequencing, including portfolios from the University of Washington and the University of Texas Southwestern, to Exact Sciences. Additionally, in February 2026, Scantox acquired TwinStrand Biosciences' nonclinical genomic safety business, including the DuplexSeq™ Mutagenesis Assays.

TwinStrand Biosciences operates as an active operating company asserting its intellectual property. The company has been involved in one tracked case as a plaintiff at the Patent Trial and Appeal Board (PTAB), Twinstrand Biosciences Inc. v. Guardant Health Inc., initiated in 2022. This PTAB proceeding was an Inter Partes Review (IPR) where Guardant Health Inc. challenged the validity of patents licensed by TwinStrand Biosciences from the University of Washington.

This PTAB challenge ran concurrently with a patent infringement lawsuit filed by TwinStrand Biosciences and the University of Washington against Guardant Health Inc. in the U.S. District Court for the District of Delaware. In November 2023, a federal jury found Guardant Health Inc. willfully infringed TwinStrand's licensed DNA sequencing patents and awarded TwinStrand Biosciences and the University of Washington $83.4 million in damages. The PTAB also issued a final decision upholding the validity of the challenged claims in the University of Washington patent.