I got some injected several time when I was a kid (for angiography). As a kid, the fun part was peeing fluorescent liquid (little I knew...).
He put each liquid component in a test tube and went out for beers. He poured one tube in a buddy's beer when he wasn't looking, and another in his next beer. Then he went in the restroom and unscrewed the lightbulb.
It would not be surprising if he was pulling my leg, we were a group of practical jokers. And this story made me swear off ever doing anything to him; in retrospect maybe that was the intent.