I’m assuming if the syringe was wet before being placed in the microscope, the vacuum of the chamber would cause most of the water in the plasma to vaporize. The remaining salts and compounds would be much smaller than the red blood cells. The density of the red blood cells would be much larger than any remaining plasma, so the bulk of your backscattered electrons will be coming from the cells and needle, making the plasma essentially transparent. This is a fairly low magnification image for SEM, but that’s how you get such fantastic depth of field.
Where is the plasma?
I’m assuming if the syringe was wet before being placed in the microscope, the vacuum of the chamber would cause most of the water in the plasma to vaporize. The remaining salts and compounds would be much smaller than the red blood cells. The density of the red blood cells would be much larger than any remaining plasma, so the bulk of your backscattered electrons will be coming from the cells and needle, making the plasma essentially transparent. This is a fairly low magnification image for SEM, but that’s how you get such fantastic depth of field.
I didn’t know electron microscopes use a vacuum chamber.
The previously donated it.