Many blood cells are visible in urine sediments, as observed in the top image. When differentiating RBCs from WBCs, it is important to use the fine focus adjustment on the microscope. WBCs have a nucleus that will be visible with the fine focus, whereas RBCs do not.
Supravital stain can also help to distinguish RBCs from WBCs. Two RBCs are indicated by blue arrows, and a WBC is indicated by the red arrow in the lower image of supravital-stained sediment.
