I will give you an example.
I'm playing with my cat Fred yesterday, and she accidentally scratched me hard enough to draw blood. Did I do what any sensible person would do and suck at my finger and moan at the soreness of my finger?
No, I said, "Hey! I could do a slide of this!" and rushed off to the microscope and prepared a blood smear.
Blood cells under the microscope at 400x magnification (the blurriness is due to the camera - it looks much sharper under the microscope - upper left is the clearest):
And, just to give you the full coolness of looking at your own blood under the microscope, here is a video of the blood being moved via capillary action between the slide and the slip:
Some really cool things to note:
- The cells stack in single file, even after they are on the slide. Red blood cells can only move in single file in the smallest capillaries like the ones at the end of your finger. So, since these came from the end of my finger, they stayed stacked that way.
- This is the very tiniest drop you can imagine. I barely was able to squeeze it from the end of my finger and yet there are THOUSANDS of cells. The blood covers about 1 cm x 1 cm on the slide and the view here is only a small portion of that, yet still there are hundreds, probably even thousands of cells in view. It's pretty impressive that they all work together.
- Not visible here, but I noticed after looking for a while are little spiky balls mixed in with the red blood cells. I thought they might be dust on the slide or something, but after looking it up on-line, they are, indeed white blood cells. They are pale, but more yellow than white and actually look like a burr that catches on your clothes in the bush.
- Even after trying hard to thin out the drop of blood, the group of cells is 3d and under full magnification, you can see the top layer and move through the layers by playing with the focus. For the first few minutes, the blood is continuing to move around.