Microscopy Solutions for Urinalysis

Urine is traditionally examined with upright light microscopes. In general, brightfield microscopes are the instrument of choice. However, urinalysis guidelines also recommend the use of microscopes equipped with phase contrast and polarized light filters to identify urine particles like dysmorphic erythrocytes and casts (phase contrast) as well as lipids and crystals (polarized light). LED illumination increases the quality of sample visualization. Standard objectives for routine urinary sediment are a 10x for casts and a 40x for cells and other smaller structures, resulting in a 100x or 400x magnification (when used with 10x eyepieces). 400x is also fine to visualize bacteria. In order to get a more detailed observation of bacterial morphology, such as shape, size, and cellular structures, 1000x magnification can be helpful. However, at a higher magnification, it can be increasingly difficult to keep them in focus as they move.