CHAPTER 7: MICROSCOPIC EXAM Flashcards
May cause precipitation of amorphous urates and phosphates and other nonpathologic crystals that can obscure other elements in the urine sediment
Refrigeration
Standard amount of urine
10 - 15 mL (12mL: frequently used)
Recommended volume when using the conventional glass-slide method
20 uL (0.02 mL)
*covered by a 22 x 22 mm glass cover slip
How many fields should be observed and in what power?
Min. of 10 fields, under both low (10x) and high (40x) power
The slide is examined in this power to detect casts and ascertain the general composition of the sediment.
low power
*locate near the edges of the cover slip
Note:
R e p o r t i n g
1) casts: ave #/10 lpf
2) RBCs & WBCs: ave#/10 hpf
3) epithelial & crystals: rare, few, mod, many (1+, 2+, ….)
Developed the first procedure to standardize the quantitation of formed elements in the urine microscopic analysis in 1926
Addis
Most frequently used stain in urinalysis which consists of crystal violet and safranin O
Sternheimer-Malbin stain
Used for the visualization of elements with low refractive indices (hyaline casts, cellular casts, mucous threads, Trichomonas)
Phase-contrast microscopy
Used for the identification of cholesterol in Oval Fat Bodies and crystals
Polarizing microscopy
This stain delineates the structure and contrasting colors of the nucleus and cytoplasm.
ID: WBCs, epithelial cells, and casts
Sternheimer-Malbin
This stain enhances nuclear detail.
Differentiates WBCs and RTE
Toluidine blue
This stain lyses RBCs and enhances nuclei of WBCs.
Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals
2% acetic acid
Stains triglycerides and neutral fats orang-red. It does not stain cholesterol.
Oil Red O and Sudan III (Lipid stains)
A stain that identifies bacterial casts either positive or negative.
Gram stain
This stain identifies urinary eosinophils
Hansel stain
Stains structures containing iron.
Identifies yellow-brown granules of hemosiderin in cells and casts
Prussian blue stain
NV:
1) RBCs
2) WBCs
1) 0-2 or 0-3/hpf
2) 0-5 or 0-8/hpf
In _______________ urine, the cells shrink due to loss of water and may appear crenated or irregularly shaped.
hypersthenuric/ hypertonic/concentrated
In _____________ urine, the cells absorb water, swell, and lyse rapidly, releasing their hemoglobin and leaving only the cell membrane.
dilute/hypotonic/hypothenuria
Large empty cells
ghost cells
RBCs that vary in size, have cellular protrusions, or are fragmented and have been associated primarily with glomerular bleeding
Dysmorphic
The dysmorphic cell most closely associated with glomerular bleeding
Acanthocyte with multiple protrusions
Predominant WBC found in the urine sediment.
Neutrophils