The X-Files, Season 2

Scully:
I just got the toxicology report back on the broken vial. The residual substance couldn't be analyzed because it contained synthetic corticosteroids with unidentified amino acids. That's "Purity Control," Mulder.

Mulder:
Do you know what you're saying, Scully?

Scully:
The man who died in that plane crash was inoculating those kids with antibodies derived from what may have been an extraterrestrial source.

Mulder:
He's been injecting those kids with alien DNA.

Scully:
No, Mulder, that was never proven conclusively.

Mulder:
But it's the same substance we found in the Erlenmeyer flask, isn't it? The same material my Deep Throat contact died for.

Scully:
Yes.

Mulder:
It all makes sense. The money in the briefcase, they've been conducting an experiment here. Somebody's been paying to have those kids injected with alien DNA to see how they'd react. It's been going on for years.