Greetings! My name is James Pelletier, and I am super excited to be a new explorer of the microcosmos through a Foldscope! I feel inspired by the beautiful images and questions on the Microcosmos site. I am thrilled to join the Foldscope community and learn from you.

This summer, we will introduce Foldscopes to the Microbial Life class at the Children’s School of Science in Woods Hole, Massachusetts. Like Tadayasu Sawaki, the protagonist of Moyasimon: Tales of Agriculture, a manga series by Masayuki Ishikawa, we will meet and communicate with diverse microorganisms!

Thank you very much to Manu Prakash and the Foldscope team!

I am a graduate student, interested in the structure and dynamics of cells. I am fascinated by reconstitution approaches: we try to take cells apart and then put the parts back together, to learn about the functional organization of cells. In particular, I am studying mechanisms of cell division in large, eukaryotic frog eggs from Xenopus laevis (see my profile picture, thanks to Holger Krisp from Ulm, Germany for the awesome photograph on Wikimedia Commons) and in small, prokaryotic mycoplasma bacteria.

Yesterday I did an experiment and took my first image using a Foldscope! From frog eggs we prepared cytoplasmic extract, which is a complex fluid that mimics the inside of a cell. Then, we used a microfluidic device, like a miniature aquarium with channels about as wide as human hair, to prepare droplets of cytoplasmic extract surrounded by oil, kind of like a salad dressing. The image shows an uncontrolled region of the device at the end of the experiment, where smaller droplets can fuse together to make larger droplets, resulting in the different sizes. The device did not fit into the Foldscope, so I temporarily taped the lens to the device and then held my phone over the lens. I was surprised how much bigger was the field of view using my phone rather than my eye, it was like stepping through the looking-glass. The droplets are tens of microns in diameter. I am quite curious to calibrate my Foldscope so I can measure sizes.

Microfluidic droplets

Thanks again to the Foldscope team!

2 Comments Add yours

  1. Manu Prakash says:

    Welcome to the Foldscope community @James.

    This is really exciting. It’s the first post I know using any reconstitution in the Foldscope community.

    Here are a few tips to improve your resolution/alignment etc.
    1) why can’t you make the droplets as an emultion; and just pipette a small portion of the “micro droplets” in a simple glass slide – put a cover slip and you are ready to mount it inside the Foldscope. The first time you put a slide; it’s a little tight but after that – it holds a slide easily.

    2) here is a adapter someone made in Foldscope community to image droplet formation inside a Foldscope – where Foldscope meets microfluidics. Take a look; this is work by @Chew; ironically – an undergrad at MIT (not so far from you).

    This is the one for live imaging of droplets

    3) watch a few “focus locking” posts which allow you to do stable “long term” time lapse imaging.
    This will allow you to see stable long term videos.

    Once you share more data – I can share more tricks. So excited to see you are tart in. To use your Foldscope.

    It would also help to share post of your materials you are using – so it’s clear why you could not mount the experiment inside the Foldscope. Will wait for your comments.

    Welcome 🙂


  2. James Pelletier says:

    Thank you very much, Manu!

    The emulsion of droplets between a microscope slide and a glass cover slip looks promising! Next post in progress.

    The microfluidic device I used is very similar to the device that Josh Guild posted on March 4, 2016 (post 13705), same material and fabrication process. Without tubing attached to the device, I can insert my device into Foldscope as Josh did. I will include images in my next post.

    The post by Chew on October 11, 2015 (post 9321) is beautiful! To attempt a similar experiment, I would alter my device to run inlet and outlet tubing from the side.

    Checking out the focus locking posts now – thank you!



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