BOSTON (AP) — The furor on Capitol Hill over Planned Parenthood has stoked a debate about the use of tissue from aborted fetuses in medical research. But U.S. scientists have been using such cells for decades to develop vaccines and seek treatments for ailments ranging from vision loss and neurological disorders to cancer and AIDS.

Anti-abortion activists set off the uproar by releasing undercover videos of Planned Parenthood officials that raise questions about whether the organization is profiting from the sale of fetal tissue. Planned Parenthood denies making any profit, saying it charges fees solely to cover its costs.

University laboratories that buy such cells strongly defend their research. They say tissue that would otherwise be thrown out has played a vital role in lifesaving medical advances and holds potential for further breakthroughs.