TARDIS laboratory

During the time the TARDIS was immobilized and everyone was acing strangely, Barbara Wright found the TARDIS laboratory. There she was assaulted by books, boxes and various bits of equipment from the benches. (PROSE: The Edge of Destruction)

The Third Doctor once recalled a time when he created a gas in the TARDIS lab which pacified a herd of rampaging volcano creatures. (COMIC: The Arkwood Experiments)

When Ace was new on board the TARDIS, she explored its interiors and found the lab. She thought it was similar to Frankenstein's lab, but with better lights. Ace didn't tell the Seventh Doctor she found it, because she knew he'd lock it up to keep her from making Nitro-9. She couldn't always find the place afterwards. (PROSE: Echo)