It was clear from the beginning that this wouldn’t be an ordinary tape night at Studio 25 on the Warner Bros. lot. As the cast and crew of “The Big Bang Theory” hit the stage to prepare for their Tuesday night taping — the show’s last, after 279 episodes — moist eyes could be seen everywhere.

“Big Bang” stars like Johnny Galecki (Leonard) and Kaley Cuoco (Penny) appeared misty eyed, and hugs were frequent before “action” was called and the final episode got underway. During the evening, Galecki, Cuoco, and Kunal Nayyar (Rajesh) took turns on the mic to thank the fans in the audience, while the rest of the cast — including Jim Parsons (Sheldon), Mayim Bialik (Amy), Melissa Rauch (Bernadette) and Simon Helberg (Howard) — also got caught in the moment. (Swept up in the moment, Parsons did a few moves to the dance music piped on to the stage in between scenes.)

The audience was receptive to the history of the moment, including a group that had camped out the night before in order to secure seats at the finale. The ringleader of that group had produced professional-quality T-shirts to mark the occasion (which many in the audience wore). Later, she told the show’s warm-up comedian, Mark Sweet, that she worked with people with autism, and that she appreciated the message of tolerance and acceptance on “Big Bang Theory,” including for those on the spectrum. Other fans also revealed how much the show meant to them, offering an escape during difficult times in their lives.

On hand were all of the “Big Bang” producers and showrunners over its 12 seasons, including creators Chuck Lorre (who held the clapboard for cameras before the final scene filmed before the studio audience) and Bill Prady. Also there: Former showrunner Steven Molaro, and current showrunner Steve Holland.

Series director Mark Cendrowski also helmed the finale, with Lorre, Prady, Molaro, and Holland all credited as writers. No spoilers, but the finale included a few surprises, an unexpected cameo and plenty of emotion.

Over the years, “The Big Bang Theory” has earned 52 Emmy Award nominations (with 10 wins to date) and seven Golden Globe nominations.

“The Big Bang Theory” premiered on Sept. 24, 2007, and remains one of the most successful sitcoms in TV history — and the longest-running multi-cam comedy ever (recently running past “Cheers,” which ended with 275 episodes).

“They were not only pleasurable but a dream come true for all of us here,” Galecki told the audience. “Please allow us to thank you. You’ve been the best fans for 12 years. You’re part of the family.”

Added Cuoco: “It’s been an honor and a joy to perform for you for 12 years. Chuck Lorre said, ‘”The Big Bang Theory” just lives on in our hearts forever.’ And it was so sweet and simple and so true.”

The series finale of “The Big Bang Theory” will air on May 16 at 8 p.m. on CBS.

The show’s cast shared the emotion with fans:

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knock, knock, knock, thank you... Thank you, apartment 4A, for being a home to so many dreams come true, to so many friendships made. And thank YOU, ALL of you - yes, YOU, reading this right NOW! As we get ready to tape our final episode tonight, to walk in and out of this apartment door for the last time, it is hard to find the words to articulate what a profound experience this has been. But the words “love” and “gratitude” come to mind... so love and gratitude to all of you. ALL of you. Thank you. ❤️ (oh! and happy birthday to @sanctionedjohnnygalecki and @kunalkarmanayyar - talk about good timing... may your next 12 years be as vibrant and wonderful as the last 12 years in which i’ve had the pleasure to know and work with you both 🎉)

A post shared by Jim Parsons (@therealjimparsons) on

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It is an overwhelming day to say the least. All of the feelings: gratitude, sadness, joy, excitement, grief...it's the end of a huge part of our lives and the beginning of who knows what. Thank you to the millions of people who love this show. Thank you for the lessons we have learned from you all. Thank you to our writers for caring so very much about these characters you all believe in and trust. Thank you for making our family a part of your family's laughter, tears, and challenges. I get to play dress up for a living and I am so honored to be a part of this cast, this crew, this staff, and this wonderful show about how these brilliant characters live, think, and love. It all started with a big bang. ❤️💥

A post shared by mayim bialik (@missmayim) on