Alligator II: The Mutation (1991)

Other mistake: David's wife is looking inside the microscope at what she describes as a protein found in the saliva. It does not quite look like a protein, and in fact it's a reused (it's exactly the same) microscope image from the previous movie, where Marisa identified it as" a section of the pituitary glans of a Lhasa Apso." (00:12:00 - 00:51:25)

Sammo