Ronnie: Be afraid. Be very afraid.
Seth Brundle: My teeth have begun to fall out. The medicine cabinet is now the Brundle Museum of Natural History. You wanna see what else is in it?
Seth Brundle: I think you're making a mistake. I think you really want to talk to me.
Ronnie: Sorry, I have three other interviews to do before this party's over.
Seth Brundle: Yeah, but they're not working on something that'll change the world as we know it.
Ronnie: They say they are.
Seth Brundle: Yeah, but they're lying. I'm not.
Seth Brundle: I was not pure. The teleporter insists on inner pure. I was not pure.
Ronnie: I don't know what you mean.
Seth Brundle: A fly... got into the... transmitter pod with me that first time, when I was alone. The computer... got confused - there weren't supposed to be two separate genetic patterns - and it decided to... uhh... splice us together. It mated us, me and the fly. We hadn't even been properly introduced.
Tawny: Are you a body builder, or something?
Seth Brundle: Yeah, I build bodies. I take them apart, and put them back together again.
Ronnie: Don't you get it? I am finally onto something that's big. Huge.
Stathis Borans: What? His cock?
Ronnie: Crude Stathis. Even for you.
Seth Brundle: There was an old lady who swallowed a fly, perhaps she'll die.
Ronnie: If you SAW him, Stathis, if you saw how scared and angry and desperate he is.
Stathis Borans: I'm sure Typhoid Mary was a very nice person too when you saw her socially.
Suggested correction: There's no possible way of teleporting physical objects either, but it happens in this movie. This is science fiction. These kinds of "factual errors" are not valid.
Phaneron ★
The film presents no scientific explanation for "teleportation" but does for "genetic merging." Teleportation is possible in this film's universe, but "genetic merging" is impossible in any universe.
Genetic merging is possible in this film's universe; that's the whole point. It doesn't matter if the explanation doesn't stack up, it still works.