The results took three to four weeks to manifest (due to preservatives, Metcalf says on her Facebook page.) The untouched slice and the slice touched by students who had washed their hands fared well. The slice touched by those who used hand sanitizer had one side which had grown a ring of mold on one side. The slice touched by students with dirty hands was covered in a layer of mold over most of its surface. The slice of bread that came in contact with the Chromebooks suffered the worst fate of all, turning a stomach-churning blue over almost all of its surface.
The teacher explained on her Facebook post that the laptop computers are sanitized on a regular basis, but not before the experiment.