That's not the main reason why we don't reuse needles.

It's a little misleading in that the last photo is zoomed in a lot more than the previous ones. This one has that without the extra zoom in.

Wow, I did not expect that.

Can we see the skin after that sixth use?

Also seems wildly overkill to use an electron microscope for this.

Yes! When I did electron microscopy, we had to cover the fix the samples and cover them with a very thin gold layer beforehand.

This is my hole. It was made for me.

Were you expecting it to be smooth like plastic? The top layer is basically a bunch of dead skin cells that keep flaking away from the top layer and building up again from the lower layers.

Scanning electron microscopes image in a vacuum. Nothing looks 100% like it does at sea level when you suck all the air out.

Environmental SEMs do not require vacuum and can be used for nonconductive samples. The beam ionizes the air which prevents the sample from charging. Magnification is limited but it is more than enough for this.

You can tell it is SEM and not optical by the depth of field. An optical image at this magnification would have much less DoF so the peaks/valleys would be blurry.

Put a needle in someone, freeze them solid with liquid nitrogen, then take a picture. Throw body out with rest of specimens.

Easy peasy.

It likely wasn't done on an electron microscope, or at least there is no reason to. There is no scale bar, but quick look online tells me a very fine needle is about 0.016in. 500x magnification optical lens would give you more than enough resolution for a photo like that.

Yes ( ͡° ͜ʖ ͡°)