1. What type of microscope depends on a special  method of illumination that increases the contrast in an unstained specimen resulting from slight variations in the thickness and refractive index of its parts?

2. What type of microscope uses two beams of polarized light in a complex optical system to visualize structures in living, unstained cells?

3. What type of microscope uses polarized light, which is split into two light beams of slightly different wavelengths, giving a three-dimensional effect to viewed specimens?

 Answers