#Bioe301C

A thin layer of onion epidermis was laid out on a slide. The cell walls, cytoplasm, as well as the nuclei are observable in the image. Onions are food that are commonly consumed by humans. Onions are often found in pizza, hamburgers, onion rings, french onion soup, and some healthy food as well such as various types of salads. Onions are also often found nearby tears. It is interesting to observe the structure of the peel, which is quite segmented and has somewhat of a crispy texture. This matches the `crunchiness’ that is often experienced when consuming or peeling an onion.

Calculation of Scale Bar

The Foldscope was calibrated with a size scale in a manner similar to that described by our wonderful teaching assistant, Xinzhi Zou, in her Foldscope #BioE301C post from last year. In this approach, we draw two lines with a 1mm distance between them using a ruler. We take a picture of these two lines using the phone camera attached to the Foldscope. Finally, we appended a line going between these two lines at one-tenth of the length of the 1mm line to the image of interest, giving us a 100 micron scale bar.

Marija Pavlovic (marijavp), Peter Washington (peter100), Kasra Naftchi-Ardebili (knaftchi)