Here I would like to show you two images of potato starch grains taken with different optical contrasting methods. The top image was taken in dark field, the bottom one in bright field. The purple or red structures are the starch grains of the potato (Solanum tuberosum). This is a nice example on how the addition of a simple field-stop filter can result in drastically different images. The contrast of the images was adjusted and both images were sharpened slightly. Image stacking was not necessary. The starch grains of potatoes are also called amyloplasts, they are found inside the cells of the potato tuber. Starch is a polysaccaride, made of long chains of glucose molecules. The glucose was originally produced by the leaves of the potato plant. Starch can be present in the form of either amylose or amylopectin. It is not water soluble and therefore suitable for storage.