Kantaro Biosciences LLC, a joint venture between the Mount Sinai Health System and RenalytixAI, has received emergency use authorization from the U.S. FDA for its semi-quantitative SARS-CoV-2 IgG antibody test kit. Known as COVID-Seroklir, the test determines the presence and precise level of IgG antibodies. It has demonstrated 98.8% sensitivity and 99.6% specificity for detecting SARS-CoV-2 specific IgG antibodies against two virus antigens, the full-length spike protein and its receptor-binding domain.