Dark-field Microscopy

Dark-field microscopy is when the light from under the specimen is partially blocked. The light does not pass directly through the sample being studied. Instead light is reflected off the specimen, making it appear to be emitting light. Dark-field image may first appear to be a negative of a bright-field image. It works well with live organisms.

 

A simple method is to use a dime placed in the middle of your microscope filter just below the microscope condenser. I recommend putting the dime or dime sized stop(made of thin cardboard coloured black) on a clear piece of plastic to protect the filter from being scratched. If the clear plastic is rigid enough you can replace it for the filter all together. Figures 1 and 2.

Figure 1

 

Figure 2

 

Since I have access to a 3D printer I decided to 3d print them. As can be seen in figure 3, I 3D printed my stops to fit in place of my filter on the microscope. I printed 2 different size stoppers 8 mm and 15 mm.

Figure 3

 

In figure 4 this is a regular image, in figure 5 I use the 8 mm stop. You can see the difference between the 2. The 8 mm stop shows more detail than without any stop. With the 15 mm stop it darkens the field way to much. Figure 6.

Figure 4

 

Figure 5

Figure 6

A very simple and inexpensive addition to many microscopes.