Recognizing Content

[DonSchaeffer]

https://www.youtube.com/watch?v=lIqMVveQY-8
I set about examining some roots that my friend had cut off a tuber plant that she was cooking. I had to cut samples of the roots thin and crush them down to make them flat for the microscope. To see anything I tried staining with food coloring (not too successful) and using vegetable oil as a mountant (that worked). I was confronted with a lot of uneven structures and some orderly structures. The question arose--what, in the mess that I'm looking at, is real and meaningful and what is mere flim-flam. This is an important question for the study of life--especially as we begin examining extra-terrestrial samples.

[Roldorf]

You need to make your samples thinner otherwise you will not be able to see the samples structure. May as well put stuff in a blender if you have to crush it to get it to fit under a cover slip.

[Hobbyst46]

You need to make your samples thinner otherwise you will not be able to see the samples structure. May as well put stuff in a blender if you have to crush it to get it to fit under a cover slip.

Cutting sufficiently thin sections from relatively hard plant parts like tubers or roots is not easy. Crushing only creates havoc as it destroys cell structures and mixes them together.

Initially thin plant parts: garlic peel, onion peel, onion leaf epidermis, algae - filamentous and others, moss, lend themselves to easy preparation, no crushing, no section cutting, and demonstrate the wonderful ordered structures as they really are. Other plants (e.g. hibiscus) can also provide thin layers.

[Roldorf]

I had the same problem trying to cut thin enough sections at the beginning. Searching the internet for solutions I came across some examples of home made microtome's and decided to make my own with the limited materials I had at hand. I made a version one which was very quickly retired for version two, which I still use today. Here is my post of that adventure:-

viewtopic.php?f=12&t=7887

I am sure that anyone with limited resources and skills could make their own.
As a caveat to that post I found that embedding the sample in a carrot was not very successful, as the carrot nearly always moved and made the section that I wanted to look at uneven on one side so that for the coverslip to sit evenly on the section, necessitated putting undue pressure on the sample ( unless of course you have very firm carrots ).

I found that packing the hole with the sample instead of carrot always gave me at least one section that was thin enough and flat enough. If the sample is very hard you can try putting the carrot on the leading edge of the blade and the sample on the trailing edge.

[mrsonchus]

It can get quite involved, but the basics are straightforward enough, as always, once you've done it a few times.
Starting with virtually no experience does I very quickly discovered tend to lead to an explosion of equipment, bits & bobs, blades everywhere, exotically stained fingers and clothes.....

Here's an old post of mine of such a scenario - once mastered to a small extent, it really does become increasingly fascinating and satisfying!

Personally I'd say the most significant factor is the sharpness o blade used - whatever that blade may be from.

[DonSchaeffer]

I have a microtome but I found it too difficult to use. Most of the time with stems and other parts I scrape then down with a razor knife--scraping off cell layers. I often have to crush them a little to get them flat enough. I think I've actually had pretty good results with most stems and leaves.

[mrsonchus]

I don't use a hand microtome for hand-sectioning either - they're far too laborious in use I find. I simply hold the part in my fingers and run the blade parallel to my finger-nail, with a tiny change of angle (from the very-nearly-vertical) another section may be cut. With a sharp blade this simple technique works very well. The sections from the old post I linked to are all cut this way, no microtome used....

[DonSchaeffer]

Another disadvantage of the microtome is that it can only be used for cross-sectional cuts. I like to see a longitudinal perspective--the long cells that make up a stem, for instance. I know there are limits to my ability to make useful slides of hard material, but I think I have enough success to warrant further attempts. Flattening may cause some distortion, but basic structures are often still visible.