Dolan tested positive for COVID-19 back in March after coming down with the usual symptoms -- including a loss of smell.

The 64-year-old quarantined himself and has been recovering ever since. Finally, a new test taken almost 4 weeks after his initial diagnosis shows he's now negative for COVID.

Now, Dolan is focusing his energy on helping others -- an MSG spokesperson confirmed to The Post he has volunteered to participate in multiple clinical trials.

In fact, he's already donated blood to multiple hospitals including NYU Langone Health and Duke University Medical Center,

Dolan has also taken steps to donate plasma antibodies to help current COVID-19 patients.

According to the Red Cross, "People who have fully recovered from COVID-19 have antibodies in their plasma that can attack the virus."

"This convalescent plasma is being evaluated as treatment for patients with serious or immediately life-threatening COVID-19 infections, or those judged by a healthcare provider to be at high risk of progression to severe or life-threatening disease."

There's more ... Dolan has also placed in $1 million into a relief fund he created for MSG employees who are taking a hit from the Garden being closed since March 12.