2.1: Numerical aperture

need dapi slides - can use the same ones for 2.2

squuze bottle of ethanol to clean oil off lenses.

Stage micrometer:

10X: 2.162 pixels/µm

40X: 8.728 pixels/µm

Reticle is 2 mm

Major divisions are 100 µm

tiniest divisions are 10 µm