TwinStrand Biosciences, a Seattle startup developing next-generation DNA sequencing technology that promises to lead to early cancer detection, rapid identification of carcinogens and other breakthroughs, has raised $16 million in a Series A funding round led by Madrona Venture Group. The company, a University of Washington spinout, says its DNA sequencing method, known as Duplex Sequencing, uses cloud technologies and advanced error-correction algorithms to allow researchers and clinicians to find rare genetic variants with 10,000 times more accuracy than standard sequencing techniques. TwinStrand, which has just under 30 employees, is planning to launch its first product this quarter.