Urine Sediment Microscopy and Instructions
(1) Obtain 10cc of urine (2) Dipstick (3) Centrifuge using a balance @ 3000 RPM x 3-5 min.
(4) Pour off supernatant and resuspend sediment with pipette; place one drop of sample on slide, place coverslip, analyze.
(5) Standard or bright field microscopy: keep light source subdued, lower condenser to maximize contrast, start at low power (10x) paying attention to coverslip edge where casts tend to migrate, increase power as needed to examine formed elements.
(6) Phase contrast microscopy: review components of phase contrast microscopy. Raise condenser up high and turn light source to maximal brightness. Rotate the condenser annulus to 40 and the objective to 40 (objective and condenser annulus should always match). Analyze for dysmorphic RBCs or casts by focusing up and down.
(7) Please use the urine sediment guide adjacent to microscope to guide analysis.
RBCs - Glomerular (dysmorphic RBCs “mickey mouse ears”) vs non-glomerular (trauma, exercise, infxn, tumor, stone, SCD)
WBCs - UTI/cystitis, pyelonephritis, AIN, atheroembolic, glomerular injury, renal/bladder TB, nephrolithiasis
Epithelial Cells - Tubular (ATN), transitional (proximal urethra to renal pelvis), squamous (contamination by genital secretions)
Casts - Viewed best w/ phase contrast: Hyaline, RBC, WBC, Muddy brown, Granular, Waxy, Fatty
Crystals - Viewed best w/ phase contrast: Acyclovir (“needles”), Tenofovir, Struvite (↑ urine pH), ethylene glycol (oxalate)
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