In an interview with TV Insider for the CBS show's final season, Cuoco, 33, said she auditioned for the show but wasn't cast because of her age. Cuoco originally auditioned for the role of Katie, a character that doesn't exist on the show but was part of the original unaired pilot. Read more: Kaley Cuoco said there were 'hysterical sobs' when the 'Big Bang Theory' cast learned the series was ending. Television Group Peter Roth said.
Kaley Cuoco was originally rejected from 'The Big Bang Theory' because she was too young
All three also served as head writers. The show premiered on CBS on September 24, and concluded on May 16, , having broadcast a total of episodes over 12 seasons. The show originally centered on five characters living in Pasadena, California : Leonard Hofstadter and Sheldon Cooper , both physicists at Caltech , who share an apartment; Penny , a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's similarly geeky and socially awkward friends and co-workers, aerospace engineer Howard Wolowitz and astrophysicist Raj Koothrappali. The show was filmed in front of a live audience and was produced by Warner Bros.
Melissa Rauch and Mayim Bialik were upgraded to the main cast during the fourth season as Dr. Bernadette Rostenkowski and Dr. Amy Farrah Fowler. Penny dates a couple of guys including the dense Zack who likes the "science dudes", Sheldon begins a platonic relationship with Amy, Howard reconnects with Bernadette eventually asking her to marry him, Leonard begins to date Raj's sister Priya, Penny becomes friends with Amy and expresses regret at breaking up with Leonard.