Hi Guys!

Do you have any microscopy questions, which you are afraid to ask? This is your place.
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RonaldRoach
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Joined: Mon Sep 18, 2017 11:44 am

Hi Guys!

#1 Post by RonaldRoach » Mon Sep 18, 2017 5:41 pm

Hi Guys.

New to the forum and have a little experience with microscopes. One thing I am curious to know is how to find particular samples? Can you follow a precise method like when looking for tardigrades in soaked moss or does luck come into play when searching for things like Protists? An example of something I am hoping to find would be Lacrymaria olor, which I believe lives in pond water but that's all the guidance I can find online.

To sum up do you have to inspect drop after drop of water until you find something of interest or can you 'culture' or accommodate particular organisms for easier access. I don't mind the water drop method if it's the best we have just don't want to do it if there is an easier method.

Hope this makes sense and thanks in advance.

billporter1456
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Joined: Thu Oct 16, 2014 12:05 am

Re: Hi Guys!

#2 Post by billporter1456 » Mon Sep 18, 2017 9:31 pm

RonaldRoach wrote:Hi Guys.

New to the forum and have a little experience with microscopes. One thing I am curious to know is how to find particular samples? Can you follow a precise method like when looking for tardigrades in soaked moss or does luck come into play when searching for things like Protists? An example of something I am hoping to find would be Lacrymaria olor, which I believe lives in pond water but that's all the guidance I can find online.

To sum up do you have to inspect drop after drop of water until you find something of interest or can you 'culture' or accommodate particular organisms for easier access. I don't mind the water drop method if it's the best we have just don't want to do it if there is an easier method.

Hope this makes sense and thanks in advance.
Your question makes perfect sense to me, but I'm not sure I'll be able to offer much help. I can tell you what I do and I have found a fair number of Lacrymaria. I just go to a little pond not far from our condo and find a place where I can get down close to the water. I use a fairly small plastic food container and scoop up some water from right at the edge of the pond, making sure I get some muck from the bottom. Also, I always make sure I get a clump or two of Algae. So I get some water from the surface and a bit of the bottom stuff. When I get home, I toss in a grain of rice or a few springs of dried grass as that will promote the growth of lots of bacteria to feed the protists. I may just scoop up a couple of ounces of pond water there at the pond and then add some bottled spring water to the container once I get home. Let everything settle for a few hours. Sometimes there will be considerably more protists after a couple of days than there were at first due to the presence of more bacteria. My method is pretty primitive and probably far from the most effective way to proceed, so I hope some experienced forum members chime in with suggestions.

Updated a bit later: I should have mentioned that simply getting an eyedropper of water from your sample container isn't likely to contain a Lacrymaria or many protists of any type. I always get at least a bit of green stuff to put on the slide and some detritus (garbage) as well. Lacrymaria likes to hide under stuff and shoot its neck out to feed, so you will want to have some stuff on the slide that might have a Lacrymaria under it.

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zzffnn
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Re: Hi Guys!

#3 Post by zzffnn » Mon Sep 18, 2017 11:39 pm

Welcome to the forum.

Finding protists mostly depends on luck, unless you can find a place that sells them.

Edit: pond vegetation and mud is a good place to start. Squeeze the vegetable, and filter mud with a filter with tiny but visible pores. Then take the filtered solution, let it sit for 5 min, then take the bottom. You should have some protists there.
Last edited by zzffnn on Tue Sep 19, 2017 3:09 am, edited 2 times in total.
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c-krebs
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Re: Hi Guys!

#4 Post by c-krebs » Tue Sep 19, 2017 1:48 am

billporter1456's approach is good and typical for collection. If there is a great deal of loose vegetation at your collection site is is also a good idea to lift up clumps of the vegetation and let it drip into your collection jar.

In addition, it is extremely helpful to have a stereo microscope to take a preliminary survey of what has been collected (or develops after a few days). Once you have an idea of the apparent sizes of certain subjects it can be pretty easy to spot "larger" subjects like water bears, testate amoeba, volvox, desmids, closterium, and most rotifers at about 20X-30X with a decent stereo. A majority of interesting subjects will not be found in "open water". They are usually found on or around plants and detritus.

If you illuminate through the side of a sample container with a bright, small light source you will often discover that there are quite a few interesting subjects that exhibit positive phototropism. They will move and congregate in significant numbers against the container wall at the location of the light. Also illuminating a sample container (on a dark surface) low and from the side creates a sort of "darkfield" light that makes it easy to spot quite small specimens.

Typically I'll draw off individuals or a promising looking piece of plant material or debris sample from my collection container and put it into a plastic petri dish. This is then studied and selections are made to place on a slide.

RonaldRoach
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Joined: Mon Sep 18, 2017 11:44 am

Re: Hi Guys!

#5 Post by RonaldRoach » Tue Sep 19, 2017 9:06 am

Thanks for the responses I will make sure I give these methods a try. I work In a school as a lab tech so I have access to some old steromicroscopes but might invest in a new one in the future. I managed to find a few tardigrades and what I imagine are Rotifers and nematodes. It's amazing to see how much life can be found in a small clump of moss.

I will attempt to attach pictures soon.

Thanks guys :)

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