yayodeanno: Which mutagen is it exactly? I accepted the job but forgot check the inventory afterward, and I think there's no journal entry about that "quest" either. Btw, I'm in Act 2 but no option to add mutagens has yet appeared in my skill tree. Must I select the skill "to form mutagens as a byproduct... mumbo jumbo"?

Aaden: No, only a few specific skills have mutagen slots, indicated by a little circle at the edge of the skill's symbol in the skill-tree.
As can be seen here - the three skills on the right side have mutagen slots, e.g.

Fuxymaxy: Are there more mutagen slots on the alchemy branch? Since you don't really have much slots, in fact more than 4 if you build up the swordsam or the wizard branch.

yayodeanno: I'd love to know the exact mutagen Geralt receives from the scientists cause the quest will probably carry to TW3 if one keeps the game saves. Really curious on how the story unfolds. So, what is the mutagen?

Paul_cz: My guess would be that CDP had to cut this quest due to lack of time. Maybe they will expand on it later for x360 version and PC version via patch.

dnna: But they do say something along the lines of "We'll talk again if we meet in Vizima" - and you don't get to visit Vizima in TW2. Or do you mean it was meant to be something bigger and they turned it into a quick 'here's your mutagen' thing last minute?