Bernadette: Still, I can't believe you can turn ordinary skin cells into functioning brain cells.
Amy: Well, I turned this one into a functioning boyfriend, so sky's the limit.

Raj: Maybe there are other things we have in common. Come dinner-time, do you enjoy eating food?

Raj: Well, I can't eat like a ten-year-old all the time.
Penny: You're dating somebody! Who is it?
Raj: What? What are you talking about?
Penny: You only watch what you eat when you're afraid you might have to take your shirt off.

Sheldon: And you realize what the next step is?
Amy: Set up a second culture and try to replicate our results.
Sheldon: Uh, no. We lock that door, lower our underpants a little, and make a baby.

Penny: How come you never eat broccoli?
Leonard: I'm married, I don't have to be attractive.

Sheldon: How much will it hurt?
Amy: It's just a tiny skin sample. You saw me do it to myself.
Sheldon: On a scale of one to ten, where one is a pebble in your shoe and ten is the monkey you thought was your pet biting your face off.
Amy: A two.
Sheldon: Eating a whole Altoid?

Sheldon: Yeah, I have to say, it is nice to share this experience with someone who's on the same journey. Although right now ours is testing off the charts while yours is floating around in its own waste.
Bernadette: Are you actually comparing my human baby to your brain in a bowl?
Sheldon: Well, I didn't make you waddle up four flights of stairs for the heck of it.
Bernadette: You do realize my baby has functioning organs and can recognize voices.
Sheldon: Yeah, but ours can recognize a specific data stream among background noise.
Bernadette: Mine has a fully developed immune system.
Sheldon: Ours doesn't need an immune system because it lives in a state-of-the-art German incubator.

Amy: Sheldon, that's enough.
Sheldon: Oh, yeah, no, fine. Let's just agree that both creations are special in their own way and it is foolish to try and compare them. Although, we didn't need to have sex with Howard for ours, so we win.

Penny: Could you two really have some sort of super-intelligent child?
Amy: Well, there is a genetic component, but that doesn't guarantee anything.
Leonard: That's true. Sheldon's father once picked a fight with a cactus.
Penny: Yeah, but that's just his Earth parents. We don't know anything about the ones that sent him here.
Leonard: Well, we know they were smart enough to send him away.

Amy: Sheldon, please stop trying to seduce me.
Sheldon: Who's trying to seduce you? After a long day I always turn on smooth jazz and spray deer musk on my inner thighs.
Amy: I thought it smelled like a petting zoo in here.
Sheldon: Anything you'd like to pet? Bu-, but not my hair. There's a lot of goop in it.

Raj: Oh my god, I just got it. Fun onions. Funyuns. Hahahaha!

Raj: It's a gravitational wobble. It could be a sign of an extrasolar planet that may contain life and someday be named after me.
Issabella: Oh well, if it has life, maybe it already has a name, huh?
Raj: Yeah, but it's probably difficult to pronounce.
Issabella: What is your name?
Raj: Rajesh Ramayan Koothrappali.
Issabella: You think it would be more difficult than that?
Raj: Good point.

Howard: No, she's right. As long as I've known you, you've always been self-conscious about your cleavage.
Raj: It's because you keep trying to stick pencils in it.

Amy: Sheldon, I'm not ready to have a baby.
Sheldon: Oh, yes, you are! I track your cycle. For the next 36 hours you're as fertile as a manure-covered wheat field.
Amy: Wow. I can actually feel the egg crawling its way back up.

Sheldon: Oh, my goodness! I see quivering black lines. Those must be neurons. Oh, they're so thick and beautiful.
Amy: Those are your eyelashes. Move!