Today during my research class, I was designing some new wet mount slides for the Foldscope and I used the week-old pond water from my last post as a test solution to see if my idea was working. Guess what. It worked! As I was panning around, I saw a Rotifer. The rapid movements of its cilia, pumping organs and contractile movements are fascinating. To think that the founder microscopy, Antonie van Leeuwenhoek first documented Rotifers a few centuries ago and being able to image these microorganisms with my Foldscope now is crazy.

Here’s my setup:

I used Marie’s Foldscope imaging station to image my slide. It gives me a lot more control focusing.

Here’s my slide prototype with the specimen already sandwiched between the plastic coverslips:

I added double stick tape to both sides of the plastic slide, then punched a hole through the tape and the slides. I then stuck a plastic coverslip to one side of the slide, creating a tiny well for me to add my sample. I finished by sticking another coverslip to the front of the slide (that already had double-stick tape on it), and then I slid the prepared wet mount slide into the Foldscope.

Here’s the Rotifer that I found:

You can see the ciliated head and slight red pigmentation within its body cavity. Moving forward, I’d like to continue testing out different wet mounts. For now, this sandwich idea looks pretty good. The layers of tape act like a slightly hydrophobic barrier but do not impede the viewing window because they completely surround the hole punch but do not cover the hole. The hole punch is small enough to contain the solution within a confined area and big enough to image a decently-sized sample. The video below gives a better visual of the Rotifer’s movements:

Note: My exclamation when the Rotifer contracted is particularly amusing (“Oh my gosh! It did something weird!”). Once again, my teacher (the environmental science teacher, Mr. Stoehr) and Ellen (whom I’ve nicknamed Ellenia in the video) make an appearance.

Alice