Accelerate Diagnostics (AXDX -5.00%) is a biotech company that is focused on accelerating diagnostic speeds for bacterial and fungal infections that lead to sepsis, one of the leading causes of death. After the COVID-19 pandemic broke out, it signed a collaboration agreement with a small private biotech, BioCheck, that had developed a fast and automated diagnostic that was capable of testing human serum for the presence of antibodies to the novel coronavirus and returning a result in 30 minutes.

On Tuesday, the two companies announced that the Food and Drug Administration had granted an emergency use authorization (EUA) for the new test. Accelerate Diagnostics has the rights to distribute the testing system in North America, Europe, and the Middle East. BioCheck's test is performed on the Sophonix MS-Fast system, also distributed by Accelerate Diagnostics and given approval under the EUA.

MS-Fast diagnostic system

Image source: Accelerate Diagnostics

This new diagnostic targets the S1 protein, also known as the spike protein, which is the major antigen of the coronavirus. As Shelley Campeau, manager of clinical trials for Accelerate Diagnostics, said in the company's press release: "The S1 protein has the fewest similarities to other coronaviruses, which allows for a lower probability of false positives due to cross reactivity. The S1 protein is also the primary target for the leading COVID-19 vaccines candidates, which are being developed to neutralize antibodies that can block the virus from infecting healthy cells."

Added Accelerate CEO Jack Phillips: "This EUA will allow for more widespread adoption of the MS-Fast serology-based COVID-19 antibody testing platform."

The stock rose almost 10% in after-hours trading. However, in early trading Wednesday, it fell back, and as of 10:27 a.m. EST was down by 5.5%.