An SEM image of blue cheese, the blue color and flavor of the cheese is due to the Penicillin fungus. It is made from cow's milk using the mold Penicillin to produce the blue-green marbling. Cheese is a good source of calcium, but contains high levels of fat. This is a false color scanning electron microscope image. The image was collected at 1,000x magnification and the length bar at the bottom of the image is 20 um.