The Collaboration Contamination
Sheldon and Raj confide in Bernadette when they can't handle Amy and Howard working together on a science project. Also, Penny and Leonard learn new tactics for how to deal with Sheldon from an unlikely source.

Cast
Johnny GaleckiLeonard Hofstadter
Jim ParsonsSheldon Cooper
Kaley CuocoPenny
Simon HelbergHoward Wolowitz
Kunal NayyarRajesh Koothrappali
Melissa RauchBernadette Rostenkowski
Mayim BialikAmy Farrah FowlerThe Big Bang Theory on tvt

