how do you find the actual diameter of a microscopic cell?

Answer 1

by using a micrometer. it is an insert placed into the eyepiece of the scope, and must be calibrated for each specific scope. the calibrations include low power, high dry, and oil immersion. for example, if looking at an object under high dry, and it measures 2 increments on the scale, you would multiply this by the calculated factor to find out how many microns across the cell is.