The cast and crew of US hit comedy The Big Bang Theory have taken part in a flashmob video on the show’s set.

During filming of a recent episode of the CBS sitcom, the studio audience - as well as showrunners Chuck Lorre, Bill Prady and Steve Molaro - were surprised with a sudden live dance routine to Carly Rae Jepsen's Call Me Maybe.

The main cast members were sitting on the show's famous couch about to start a take when the summer pop hit began playing in the background.

Initially feigning confusion, the cast including Kaley Cuoco (Penny), Kunal Nayyar (Raj), Simon Helberg (Howard), Mayim Bialik (Amy) and Melissa Rauch (Bernadette) join with the crew members in the dance.

Johnny Galecki (Leonard) also eventually joins in, while Jim Parsons (Sheldon) remains standing in the background. But following the dance, Parsons utters Sheldon's catchphrase, "Bazinga".

The mastermind behind the stunt was Kaley Cuoco, who later posted the video on the show's official Facebook page. She wrote:

"This literally was the best night of my entire life. A special thanks to the cast and badass crew, for going all in, and making it a night to remember!"

Click here to see the YouTube clip.

You can watch The Big Bang Theory on RTÉ Two on Thursdays at 7pm.