After conducting a bacterial transformation lab with my students, where we genetically engineer the bacteria to make a jellyfish protein that fluoresces, we always jump into the discussion of why this technique is important.  I always try to get the students to think of ways that this could benefit them.

Among other uses, we finally get to the idea that these bacterial cells can be used as factories to make any protein you want, even human proteins.  It all depends on what recipe, or gene, you give them.  If you give them the recipe to make human insulin, they will. And then More >