NEW YORK -- After testing positive for the coronavirus, New York Knicks owner James Dolan has now recovered and is volunteering to donate blood plasma for various medical trials, a team spokesperson confirmed to ESPN.

Dolan's second test -- nearly 3½ weeks after the positive test result -- was negative. He has registered to donate plasma to several New York-based hospitals and has already given blood to NYU Langone Health and Duke University Medical Center.

The antibody tests are widely regarded as a key to developing a better understanding of the virus and, perhaps, a treatment.

Dolan's donations were first reported by the New York Post.

In a statement put out by the Knicks on March 28, the team said that Dolan, 64, was experiencing "little to no symptoms" and was self-isolating. During his illness, Dolan continued his executive chairman duties from his home.

New York has had the most coronavirus cases of any U.S. state. As of Wednesday afternoon, there were over 138,000 COVID-19 cases and 9,944 confirmed deaths in New York, according to local government officials. There is a total of 802,583 confirmed cases in the United States.

The NBA has been on pause since mid-March, and Madison Square Garden -- home to the Knicks and New York Rangers and used for various concerts -- has been closed. Dolan started a relief fund to ensure that arena employees were compensated through May 3. This week, the Garden sent out an internal email extending that date through May 31.

When the NBA halted its season, the Knicks were 21-45.