An antiproton chamber was a device used in antiproton therapy sessions, which counteracted the genetic unspooling caused by acute radiation syndrome using a recombination process.
An antiproton chamber was present in the sickbay of the USS Shenzhou. In 2256, Doctor Nambue used it on an unconscious Michael Burnham following her exploration of the Klingon Beacon of Kahless. When she abruptly awoke three hours after having been beamed aboard the ship, she left the chamber before the recombination process was even reaching completion. Objecting, Nambue insistently told her that he needed her to return to the chamber. (DIS: "The Vulcan Hello")
It is unclear, in "The Vulcan Hello", whether the term "antiproton chamber" refers to the medical apparatus or a small room the technology is used in. In AT: "The Wolf Inside", the apparatus is referred to as a "DNA chamber", and it is explained how the prop was repurposed to become a set piece in Sarek's tent on the planet Harlak in "The Wolf Inside", for which a concept diagram was illustrated.