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Some notes on a few animal cell images...

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#1 Microscopy

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Posted 30 March 2019 - 01:39 PM

Here are some animal cell pictures. These are made at different magnifications, using very simple means: think of an old Olympus GB microscope and a small HP camera, hand held above the eyepiece.

Animalcells1-4-annot-2.jpg

 

Picture 1: human epithelium cells from the cheek, permanent home made slide, stained with H&E (which stands for haematoxylin and eosin).
The blue arrows point at some diplococci, who often arrange in streptococcus alike rows. These are normal commensal (thus harmless) inhabitants of the mouth.
One can imagine the arrangement of the diplcocci, as 2 coffee beans, laying with the flat side towards each other. These are very small structures and the diplococci can only be separated optically with a system having an N.A. > 1. Kind of double stars at the microscopic level ;-).

 

Picture 2: section through the seminal vesicles of an earthworm (Lumbricus sp.) with several stages of the spermatogenesis (through meiosis) visible, permanent home made slide, stained with H&E. :

 

Picture 3: a smear of the contents of the seminal vesicles of an earthworm (Lumbricus sp.) showing earlier stages of the sperm forming cels shown in picture 2. Permanent home made slide, stained with H&E. The picture is beyond "usefull magnification"

 

Picture 4: a section of mammal (rabbit) liver, permanent home made slide, stained with Heidenhain's iron haematoxylin.

 

 

Notice some differences between the images:

The nuclei in the human squamous epithelium cells from the cheek show litlle detail, apart from some hardly visible and poorly stained grains.
Compare with the other pictures: in all three of them the nuclei show abundant detail: the small dots and lines of the chromatin network, stained blue in pictures 2 and 3 and gray in picture 4.

 

Notice the presence of nucleoli in the nuclei, easy visible in the third picture as pink stained dots, but recognisable in pictures 2 and 4 as well (I pointed a few out, black arrows). Nucleoli are a normal feature of healthy, live interphase cell nuclei in both animal and plant cells.

 

 

Also notice the difference in nucleus/protoplasm ratio: in the squamous epithelium cells, the nucleus is very small, compared to the cell outlines.
Cell outlines are difficult to see in sections of animal tissue (due to the lack of cell walls), but they're usually clearly visible in smears, especialy when a dye is used to stain the cytoplasm.

Compare picture 1 with picture 3: while the dimensions of the nuclei in the cells in picture 1 are negligible compared with the cytoplasm, the nuclei in the cells in picture 3 account for some (gross estimation) 70% of the cell image surface.
Allthough it's difficult to see in picture 2, it will be pretty much the same situation as in picture 3.

 

Or compare picture 1 with picture 4, in which a hint of the cell membrames is more or less visible in the liver parenchyma, due to the action of the ammonium-iron III sulfate used in the Heidenhain iron haematoxylin staining technique.

 

I find that all interesting, don't you?


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#2 Hesiod

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Posted 30 March 2019 - 01:43 PM

It remembers me when was at the university


Edited by Hesiod, 30 March 2019 - 01:43 PM.


#3 SkyHunter1

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Posted 30 March 2019 - 02:32 PM

Very cool!!! I'm an AP guy but love the micro images too :)



#4 TOMDEY

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Posted 30 March 2019 - 02:35 PM

Hand-held above the eyepiece... outstanding!    Tom




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