CHICAGO (CBS) – The Howard Brown Health Center, a medical clinic that has tended to the gay and lesbian community for 36 years, has received a sizable grant from an anonymous donor amid dangers of closing.

The health center, located at 4025 N. Sheridan Rd. in the Uptown neighborhood, announced Tuesday that it had received a $100,000 challenge grant from an anonymous donor. The donor will match all donations one-to-one up to $100,000.

The donor’s son was treated at Howard Brown, but he prefers to remain anonymous, according to the health center. In making the donation he said, “we can’t let this happen; we can’t let Howard Brown fail,” a Howard Brown news release said.

The health center announced this past Thursday that it was seeking to raise $500,000 in 50 days to avoid shutting its doors.

Right away, donations began streaming in. Howard Brown says within five days, it had raised $90,000 before the challenge grant came in.

The challenge grant is contingent on $100,000 being raised by Nov. 30.

Howard Brown serves about 36,000 people a year. The health center was founded in 1974, and opened its first clinic two years later.

The health center now offers everything from HIV and STD testing and prevention, to medical care and counseling. Howard Brown also operates the Triad Health practice at Advocate Illinois Masonic Medical Center, the Broadway Youth Center, and the three Brown Elephant resale shops in the Boystown and Andersonville neighborhoods and in Oak Park.

But the health center was jeopardized by the mismanagement of $3 million dollars in federal grant funds between 2006 and 2010. Internal investigations revealed the money was used to cover operating expenses, which led to the firing of two top administrators.

Howard Brown officials say the health center is a step closer to securing its future.

“Our challenge donor has bolstered our much needed lifeline, because he and his family believe in us and the work we do. That has and will make all of the difference for our future,” Howard Brown president and chief executive officer Jamal Edwards said in the news release. “We reached out to the community for a lifeline, and people are responding. We still have a lot to do before the deadline, but because of this generous donor’s challenge grant, gift can now count twice toward the goal. A donation of $25 will be $50 and $75 will be $150.”