if you've ever done an hplc with triflouracetic acid, I promise you there's residual tfa in there, even after a round of lyophilization. Though typically I'm not putting HPLC preps in my mouth. The burney/tingley sensation on my tongue was unmistakable and very reminiscent of the residual feel you get after pipetting 100% TFA in the hood.

I strongly believe that this startup did not know that about TFA, but it's basic common knowledge if you're in a reputable protein biochemistry lab (and you're paying attention). When you're moving fast to show something for demo day, you're going to use whatever you have around to do your protein preps, because TFA is standard practice.

Anyways, if any VCs want a Burton Guster to super sniff questionable biotechs, I'd be happy to do a bit of consulting on the side.