Tips on Viewing Life in a Water Drop

I’ve been trying to image life in a water drop under the foldscope, and found it trickier than I expected. Here’s a video of a recent attempt.

I don’t recognize any of the things I’m looking at, so if anything looks familiar to you, please drop a note in the comments.

Anyway, I reached out to Manu for some pointers on imaging life in water. I’m pasting below his response.

Really nice 🙂 Water from a pond has almost an unbounded diversity of life; once you get a hang of how to make slides – it’s really incredible. For an example – see this post: https://microcosmos.foldscope.com/?p=3500

Tips:
1) I think you are using the 450x lens in that video; a lower mag larger field of the view 150x lens is a better starting choice.

2) Live water samples requires making slides well. Use a glass slide for best resolution. Put two pieces of tape on two side (double sided tape is provided in the kit); put cover slip on the top. This allows just enough space for the organisms to survive.

3) Collect a drop of water from someplace which has a slightly “green” color – due to some algae growth. That’s the best indication that the water is not so polluted that it kills everything – frankly; anytime I have sampled water – it’s always got an incredible diversity.

Looking forward to trying these tips out!

7 Comments Add yours

  1. laksiyer says:

    Nice video, I am sure you are that close to catching something interesting.

    If you are collecting pond water collect it with vegetation or aquatic plants. If it is from a puddle, and if green or if you see stuff moving in it, you are in luck. Some other tips I have used are from Richard Howey’s articles.

    1. http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artjan01/rhlab4.html

    2. http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov02/rhculture.html

  2. aatish says:

    @laksiyer Thanks for the tips! Those links are interesting and quite helpful. Also good idea to collect water with plants in it, I think that will help.

    I’ve probably made about 10 attempts to image life in pond water by now. I haven’t yet seen anything particularly interesting. Here are a couple of challenges I’ve been running into, and what I did about it.

    – Not enough room for organisms to survive: I tried Manu’s idea of putting two pieces of double sided tape and bridging the cover slip over them. I found it helped too if I added 1 layer of regular scotch tape below each piece of double sided tape, so I get a little more room for water under the cover slip. Also using the glass slides and cover slip helped tremendously over the paper slides and tape method.. I get a much cleaner image.

    – Hard to focus on a transparent medium: Here the problem seemed to be that in addition to difficulty of focusing on a narrow layer, my iPhone wouldn’t know how to focus its lens and so I get a blurry image. I ended up making sure that the water drop has some visible bits of green gunk in it. These were big enough to help me focus on them, and I could get some sharp images of the green stuff so I know the setup works.

    But I’ve yet to see anything alive and moving. I think I might just need to be patient and keep trying water from different places / multiple samples of water. I got a jar of water from the Hauz Khas reservoir where the water is alarmingly green (see e.g. https://en.wikipedia.org/wiki/Hauz_Khas_Complex#/media/File:Ferozesha_tomb_at_the_left_end_with_Northern_limb_of_the_Madrasa.JPG ) but haven’t yet seen anything very interesting. If I eventually get it working well, I might take a video of how to make a wet slide.. I think that would have been helpful for me to see.

    Thanks again for your help!

  3. Manu says:

    @aatish: making a video of how to make wet slides – will be super useful for everyone.

    Sampling water is like an expedition looking for tigers – when you see the rare ciliates; your heart is filled with joy 🙂 but if you always get some debris – at least organisms that mount (vorticella) come for free. Also, leaving the water for a day increases density of a few “winners” in this limited ecosystem.

    Cheers
    Manu

  4. laksiyer says:

    There is one other trick that I have used. Take some boiled rice or wheat grain (5-10 grains would do and put it into your bottle and wait for 48 hours and then sample it. Else you can make a hay infusion. Boil hay and water in a microwave for 5 minutes and after it cools down, pour about 10ml of that supernatent for 100 ml of your sampe, wait for 48 hours.. First the fast growing bacteria take over the medium, then the ciliates that grow on these increase in population.. Fun stuff.

  5. Saad Bhamla says:

    @laks – Ooh! thats a cool idea. I was having a similar problem with very few micro-organisms. I never thought of the idea of feeding them for a day or two, and then checking again!

    I’m going to try it on my sample at home 🙂

    Saad

  6. laksiyer says:

    Yes @Saad, hopefully that will work.. I have read of many other tricks that I havent tried. For example, milk powder is a great favorite for some and also lettuce. Richard Howey has some really good posts on this.
    http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/artnov02/rhculture.html

  7. ibfoldscope says:

    how to see water from fold scope

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