Press Releases

FDA Adds Kantaro’s Semi-Quantitative COVID-19 Antibody Test to Revised Emergency Use Authorization for Convalescent Plasma

  • COVID-SeroKlir is a high-performance test that detects the presence and precise level of SARS-CoV-2 IgG antibodies

NEW YORK, Feb. 10, 2021 — Kantaro Biosciences, LLC, a joint venture between the Mount Sinai Health System and RenalytixAI (LSE:RENX /NASDAQ: RNLX), and manufacturing partner Bio-Techne Corporation (NASDAQ: TECH), announced that the U.S. Food and Drug Administration (FDA) has added COVID-SeroKlir to the Emergency Use Authorization (EUA) for the use of convalescent plasma for treating COVID-19 in hospitalized patients. COVID-SeroKlir detects the presence and precise level of SARS-CoV-2 IgG antibodies with 98.8% sensitivity and 99.6% specificity.

The revised EUA qualifies the COVID-SeroKlir test for detecting high titer COVID-19 convalescent plasma during manufacturing. The EUA limits the use of high titer COVID-19 convalescent plasma only to treat hospitalized patients early in the disease course. COVID-19 convalescent plasma is an investigational product and is not currently approved or licensed for any indication.

“We are pleased the FDA has added Kantaro’s COVID-SeroKlir antibody test to the EUA for convalescent plasma and authorized the test’s use in qualifying convalescent plasma titers,” said Erik Lium, PhD, Chairman of the Board of Kantaro and Executive Vice President and Chief Commercial Innovation Officer at the Mount Sinai Health System. “We believe semi-quantitative antibody testing can play an important role in the development of advanced therapeutics for COVID-19 and appreciate that it is being recognized as such.”

The high performance of COVID-SeroKlir results from a two-step process that detects antibodies against two virus antigens, the full-length spike protein and its receptor-binding domain. This precision makes the Kantaro test accurate, with a low potential for false results. Mount Sinai developed the test’s underlying technology, which has been used close to 90,000 times on a highly diverse patient population. COVID-SeroKlir received Emergency Use Authorization by the FDA in November 2020.

About Kantaro Biosciences

Kantaro Biosciences, a joint venture between the Mount Sinai Health System and RenalytixAI, is dedicated to ensuring that high-quality diagnostic tests for critical health challenges are accessible. The company provides rigorous, results-driven and reproducible diagnostics to advance the care and well-being of people, communities and society. Kantaro specializes in the rapid scale-up of groundbreaking diagnostic innovations and the creation of partnerships to bring these crucial technologies to market. For more information, visit and follow Kantaro on Twitter @kantarobio.

About Bio-Techne Corporation

Bio-Techne Corporation (NASDAQ: TECH) is a global life sciences company providing innovative tools and bioactive reagents for the research and clinical diagnostic communities. Bio-Techne products assist scientific investigations into biological processes and the nature and progress of specific diseases. They aid in drug discovery efforts and provide the means for accurate clinical tests and diagnoses. With thousands of products in its portfolio, Bio-Techne generated approximately $739 million in net sales in fiscal 2020 and has over 2,300 employees worldwide. For more information on Bio-Techne and its brands, please visit

About Renalytix AI plc

RenalytixAI is a developer of artificial intelligence-enabled clinical in vitro diagnostic solutions for kidney disease, one of the most common and costly chronic medical conditions globally. The Company’s products are being designed to make significant improvements in kidney disease diagnosis, transplant management, clinical care, patient stratification for drug clinical trials, and drug target discovery. For more information, visit