Amy: I'm leading a study to see if deficiency of the monoamine oxidase enzyme leads to paralysing fear in monkies.
Bernadette: If they're anything like humans, the answer is yes.
Amy: You've done this experiment on humans?
Bernadette: You mean like death row inmates with nothing to lose? No, that would be unethical.

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

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!

Sheldon: *knocks three times* Amy, Bernadette, Penny. *repeats three times*
Bernadette: He's never going to stop doing that, is he?
Amy: I don't mind. I'm hoping to put his love of repetition to good use someday.

Howard: My arm is feeling numb. *Howard rubs his right arm*
Bernadette: That's the wrong arm for a heart-attack, doofus.
*Howard switches to his left arm*

Amy: It's actually steamier than it looks. Sheldon's looking up the phallic symbolism of root vegetables in renaissance paintings.
Sheldon: Oh no, I got bored of that. I'm just browsing cuticle scissors on Amazon.