These cells crawl around in your body and keep you healthy

Phagocytes are white blood cells that engulf bacteria that have found their way into the body. They are part of cellular immunity. In this video we can see them move about.

If you want to see them yourself, here are a few tips:
1. They move slowly, so be patient.
2. Close the condenser all the way to get a good contrast and depth of field.
3. Use a small drop of blood only. This way the cells are spread over a larger area and they can be seen more easily.
4. Wait until the blood stopped moving under the microscope slide.

Technical Details:
Contrasting system used: Differential Interference Contrast (DIC)
Magnification: with the exception of the overview clips of the Red Blood Cells at the beginning, all clips were filmed using a 100x oil immersion objective. The total magnification on screen differs, because I cropped the videos.
Camera: Canon EOS 70D, 4K video original footage and then converted to 1080p for Youtube.
Scale bar: was not included due to different magnifications. The diameter of one Red Blood Cell is 8 microns (8 micrometers).