FIG. 1.

Refractive index matching as demonstrated with a constant solid phase (glass bead) and various common immersion media: water (A), 80% glycerol (B), and microscopy immersion oil (C), with refractive indices (RI) as indicated. The bead has a refractive index of approximately 1.55 and therefore is almost completely transparent in immersion oil (as shown by color similarity); note, however, that light transmission is attenuated significantly by the immersion medium (implying higher absorption), as indicated by the lighter background color compared to that in panel A (for example). Scale bar, 200 μm.