Howard: Oh, Bernie. What happened?
Bernadette: Let's just say the next time you move a dozen vials of raccoon virus to the fridge, make two trips.

Howard: I'm sorry I didn't take you to the airport. I just want you to know I'll never forgive myself for being so selfish. And I promise to keep you close for the rest of my life.
Bernadette: Oh, no, that thing's gonna end up in my bedroom.

Bernadette: (Shouting from the bathroom) How many times do I have to tell you to replace the toilet paper when it's empty?
Howard: I'm in the middle of something.
Bernadette: So am I!

Bernadette: Gosh, Amy. I'm sensing a little hostility. Is it maybe because like Sheldon's work, your sex life is also theoretical?

Sheldon: Sheldon Cooper does not get lucky.
Amy: You and me both, brother.

Sheldon: I've got to find a way to stop this thing.
Leonard: Buddy, I don't think you can. Once it's out there, it's out there. This thing is like the science equivalent of a sex tape.
Sheldon: Frankly, I'd prefer a sex tape.
Leonard: You don't know what a sex tape is, do you?
Sheldon: No.

Bernadette: Great news. A raccoon virus just crossed the species barrier and can now infect humans.
Raj: Why is that great news?
Bernadette: In the pharmaceutical business we have a saying: mo' infections, mo' money.