Shares of Twist Bioscience Corp. /zigman2/quotes/207089457/composite TWST -4.53% were down 1.6% in premarket trading on Wednesday after the company said its in-vitro diagnostic test that can detect SARS-CoV-2 RNA received emergency authorization in the U.S. Twist's test can identify the presence of the virus from a patient sample; it can also be used by Biotia Inc.'s software system to analyze the sequence and detect any genetic variants. So-called "variants of concern" have emerged over the last six months, including the B.1.1.7 variant out of the U.K., which is thought to be more infectious and makes up to 30% of all new U.S. cases, according to the Centers for Disease Control and Prevention. "This test opens the door to a new diagnostic method and can also guide vaccine research, since it captures viral variants so well," Biotia co-founder Christopher Mason said in a news release. Biota is a privately held company. Twist's stock has soared 390.6% over the past 12 months, while the broader S&P 500 /zigman2/quotes/210599714/realtime SPX -1.84% is up 74.8%.