Onion Cells Under the Foldscope: Microscopic A’peel


A quick post as I’m on the road. My friend Upasana made this great slide of a thin, translucent slice of onion skin. Here’s a video of what we saw under the foldscope.

I love the sharpness of detail with which you can make out the individual cells. Also, are there some gaps between cells (intercellular spaces) visible in this video (particularly right at the end)?

Interesting too that the cells are rectangular and oblong. The chef Kenji Lopez claims that “the direction you slice your onions will affect the number of cells you [rupture]”, which he claims then affects the overall flavor (i.e. how pungent the raw onions taste). That seems to make sense, given the oblong shape of the cells, but it might be interesting to cut this in both directions and see what it looks / tastes like.

P.S. As a preview of something else we’re working on imaging, here’s a mosquito wing. I’m curious about those little bristles on the wing tips. (Click here for a different look at those structures.) I wonder what they’re for?

mosquito wing

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