Red Blood Cells

After assembling my foldscope, my first impulse was to take a drop of my blood and image it. Sadly,  the result was not as good as I expected.

Sample of my blood
Sample of my blood

Blood is a very complex fluid, it packs a large amount of cells, and a thick sample as the one I imaged is going to produce a bad image. Light is coming from everywhere in the sample, and the image will be very blurry.

My second attempt came after reading this post:

First, I need a very thin sample, just one cell thick. In order to get it, I put a drop of blood on a coverslip, and with a second coverslip I smeared the blood. And the result is strikingly good. In order to check the progress, I covered the smeared sample with a second coverslip, sealed it, and had a look under the microscope. And surprisingly, I was able to see the Red Blood Cells!

Untreated Red Blood Cells
Untreated Red Blood Cells

The Red Blood Cells are clearly visible and their biconcave shape is apparent.

Then, I decided to go a step further, fix the cells and stain them. I went around the house, and the most promising staining that I found was iodine. Iodine is an antiseptic, present in most medicine cabinets. It has a deep red color, and it reacts with starch and sugars, changing to a purple-blue color. My hope was that, if it attaches to membranes and structures, it would remain redish, and if it attaches to nuclear material, it would turn bluish. So, I fixed the sample with 95% ethanol. After 5 minutes, I rinsed it several times with water. I covered the sample with 1% iodine solution, and rinsed it again several times with water. I covered the sample with a second coverslip and sealed it. When imaging the sample so treated, I get clearly distinguishable pale-red Red Blood Cells (sorry if the color is not so apparent in the pictures), but unfortunately, no nuclei, so I was not able to see any white blood cells.

RBC stained with iodineRBC stained with iodine






3 Comments Add yours

  1. Manu Prakash says:

    Beautiful work @Manuel. I really like the images and the stains. Keep an eye for neutrophils – specially if you can get them live. This way you can recreate the famous movie where a neutrophil chases a bacteria

    An easy way to isolate neutrophils is to put a drop of fresh blood on a cover slip and keep it on your skin (37 C) for a minute or two. The neutrophil will stick while you can wash off the blood cells.

    Give it a try; it would be incredible to recreate the famous movie using a foldscope 🙂


  2. manu_g says:

    Well, my next idea was with a different sample, but now I want to try this. The goal behind not staining the sample (second image) was to try and keep everything alive, and it turns out we can get a good enough contrast. I will try the temperature trick and upload the results. Thank you for the idea.

  3. laksiyer says:

    This looks really great. That trick to get neutrophils is amazing, need to try it. With eosin and methylene blue, you should be able to see WBCs too.

    All the best.

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