Microscopic Urine Examination

Abnormalities in the physical and chemical portions of urinalysis

Chemical sieving

12 mL

10–15 mL

400 RCF

5 minutes

0.5–1.0 mL

20 µL or 0.02 mL

22 × 22 mm

10 LPE and 10 HPE under reduced light

Centrifuge 3 mL of urine

Examine the sediment without centrifugation

RCF = 105 × radius in centimeters × RPM²

Low-power objective (LPO)

Casts

High-power objective (HPO)

A quantitative measure of formed elements in urine using a hemacytometer

12-hour urine specimen

Formalin

0–500,000

0–1,800,000

0–1,800,000

0–5,000

In the objective lens, adjusted near the specimen

In the eyepiece or ocular lens

The ability to distinguish two small objects that are a specific distance apart

Microscopes require minimal adjustment when switching between objectives

To remove dust from the optical surfaces of the microscope

Cleaning the optical surfaces of the microscope

Cleaning contaminated lenses

Use dry lens paper first, followed by lens paper moistened with lens cleaner

Because of its toxic fumes

Adjust for focusing differences between the eyes

Adjusts for comfort

Loosened to rotate the microscope head

Provides ease in specimen manipulation

Rotates the objective lenses

Form the primary magnification or initial image of the specimen

Restricts the area of illumination

Adjusts the size of the field diaphragm opening

Brings the slide into view

Sharpens the image

Holds the light source

The distance between the eyes

Rotate to adjust for interpupillary distance and magnify the image formed by the objective lens by 10×

Holds the slide in place

Move the slide on the stage

Focuses light onto the slide

Holds the specimen

Loosened to remove the stage

Adjusts the size of the condenser opening

Acts as an aperture diaphragm that controls light

Center the field of view

Turns the microscope on or off and adjusts light intensity

Routine urinalysis

Enhances visualization of translucent elements with low refractive indices, such as casts

Replace the objective lens and condenser with a PC objective lens and PC condenser

The presence or absence of birefringence

The ability of an element to refract light in two dimensions at 90° to each other

Cholesterol in oval fat bodies, fatty casts, and crystals

Add two filters: one below the condenser and one between the objective and ocular lenses

Treponema pallidum

Replace the condenser with a DF condenser containing an opaque disk

Visualization of fluorescent substances and microorganisms

Provides 3-D microscopy images and layer-by-layer imaging of a specimen

Yes

Nomarski (Differential Interference Contrast) and Hoffman (Modulation Contrast)

Crystal violet + Safranin O; Available as KOVA and Sedi stain; Delineates structures and provides contrasting colors to the nucleus and cytoplasm; Identifies WBCs, epithelial cells, and casts; Most commonly used urine sediment stain.

Supravital stain; Enhances nuclear detail; Differentiates WBCs from renal tubular epithelial (RTE) cells.

Lyses RBCs; Enhances WBC nuclei; Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals.

Oil Red O and Sudan III; Stain triglycerides and neutral fats orange-red; Identify free fat droplets, lipid-containing cells, and casts; Cannot stain cholesterol.

Differentiates Gram-positive from Gram-negative bacteria; Identifies bacterial casts.

Eosin Y + Methylene blue; Stains eosinophilic granules; Identifies urinary eosinophils.

Stains iron-containing structures; Identifies hemosiderin granules.

Phenathridine (orange) stains DNA; Carbocyanine (green) stains nuclear membranes, mitochondria, and cell membranes.

Sysmex UF-100 Urine Cell Analyzer.

Presence of RBCs in urine; 0–2 or 0–3/HPF.

Smooth, non-nucleated, biconcave disks.

Hypertonic: Crenated or shrunken; Hypotonic: Swollen and hemolyzed, forming ghost cells.

Dysmorphic RBCs with projections and fragmentation.

Yeasts, oil droplets, air bubbles, and monohydrate calcium oxalate crystals; Add 2% acetic acid, which lyses RBCs but not these other structures.

Increased WBCs in urine; Normal value: 0–5 or 0–8/HPF.

WBCs are larger than RBCs; Increased numbers indicate infection or inflammation.

Most predominant WBC; Granulated and multilobed.

Neutrophils that swell in hypotonic urine; Their granules undergo Brownian movement, producing a sparkling appearance.

They form blebs and finger-like projections called myelin forms.

Normal: 1%; Significant: More than 1%.

Drug-induced interstitial nephritis.

Lymphocytes, monocytes, macrophages, and histiocytes; Normally present in small numbers.

Increased lymphocytes: Renal transplant rejection; Increased monocytes and histiocytes: Chronic inflammation and radiation therapy.

Glitter cells: Pale blue; Leukocytes: Pale pink.

Squamous epithelial cells (SEC) and transitional epithelial cells (TEC).

Largest urinary epithelial cells; Abundant, irregular cytoplasm with a prominent nucleus; 30–50 µm or 5–7 times the size of an RBC.

Approximately the same size.

Vaginal lining, female urethra, and lower male urethra; More commonly found in female patients.

Squamous epithelial cells covered with Gardnerella vaginalis; Associated with bacterial vaginosis.

20–30 µm or 4–6 times the size of an RBC; Spherical, polyhedral, or caudate; Centrally located nucleus.

Urothelial or bladder cells; Originate from the renal pelvis, calyces, ureter, urinary bladder, and upper male urethra.

Following catheterization; May appear singly, in pairs, or in clumps called syncytia.

Malignancy or viral infection.

Most clinically significant urinary epithelial cells; Origin: Nephron; Size: 3–5 times larger than RBCs.

Rectangular, polyhedral, cuboidal, or columnar; Eccentric nucleus; May be bilirubin-stained or hemosiderin-laden.

RTE cells from the distal convoluted tubule (DCT).

Indicates tubular injury.

Oval fat bodies and bubble cells.

Lipid-containing RTE cells (may also be monocytes/macrophages); Seen in lipiduria, such as nephrotic syndrome.

Lipid stains identify triglycerides and neutral fats; Polarizing microscopy identifies cholesterol through Maltese cross formation.

An RTE cell with non-lipid vacuoles; Forms when the endoplasmic reticulum dilates in injured cells before cell death.

Acute tubular necrosis (ATN).

True UTI: Bacteria + WBCs; Bacteria alone: Contamination or an old specimen.

Enterobacteriaceae (especially E. coli); Staphylococcus; Enterococcus.

Escherichia coli (E. coli), an Enterobacteriaceae member.

By observing motility.

True infection: Yeast + WBCs; Yeast alone: Contamination.

Small, refractile, oval structures that may or may not bud; Branched mycelial forms may occur in severe infections.

Candida albicans.

Trichomonas vaginalis; Pear-shaped flagellate with jerky motility.

Ping-Pong disease.

Rare, few, moderate, or many per HPF.

WBCs, transitional epithelial cells (TECs), or renal tubular epithelial cells (RTEs).

Enterobius vermicularis egg.

Blood fluke egg with a terminal spine; Causes hematuria; Associated with bladder cancer.

Trichuris, Strongyloides, Giardia, and various amoebae.

Lice, fleas, bedbugs, mites, and ticks.

NMP (Nuclear Matrix Protein) and BTA (Bladder Tumor Antigen).

Oval, slightly tapered head; Long, flagella-like tail; May be present after sexual intercourse.

Low refractive index; Major constituent is Tamm-Horsfall protein (Uromodulin).