After the room was deserted for the day, he puttsed around a bit; wiping a table here, straightening beakers there. Then he went to the greenhouse attached to his classroom to check on some plants. They were interesting specimens, never observed by his keen bespectacled eyes before. He checked to see if the DNA fragments he had collected in a test tube had been replicated since yesterday. They had, to his satisfaction.
Goopy DNA in wells at the top, he ran his perpetually-scuffed hands lightly over the starchy clear gel. Then he applied the charge: negative up top near the wells, positive down at the other end.
After a time it shut off. He checked the banding, compared it to a control plant, adjusted his glasses, & grinned.

The plant furthest to the right, compared with the control, would go perfectly on his next pizza.