Board Thread:General Discussion/@comment-27414715-20160302213117/@comment-26347196-20160303155603

That's also another thing. There's already a decently farfetched theory that Undyne once worked with Alphys in testing determination (evidenced in Undyne melting before turning to dust), but it's even more unlikely that Undyne works for Gaster. I don't recall Sans helping Alphys in helping with the amalgamates, but they both have scientific background, and it is heavily canonically implied that Alphys knows Sans (see True Pacifist route).