Lesson 4.1: Urinary Sediments - Cells/Casts/Parasites Flashcards
3 primary Formed Elements
RBCs
WBCs
Hyaline casts
Formed elements disintegrate rapidly in dilute _________ urine
alkaline
What may cause precipitation of amorphous urates and phosphates?
Refrigeration
What specimen collection procedure for urine minimizes external contamination of sediment?
Clean-catch midstream
False positive or False Negative
Dilute random specimens
False-negative
Technical Tip: Warm refrigerated urine specimens to 37C before centrifuging to dissolve amorphous urate crystals
Okay! Thanks gid!
For specimen volume, what is the standard amount of urine
10-15mL
In a urine specimen volume, how much is usually used?
12-mL
Centrifugation for __ minutes at a relative centrifugal force (RCF) of ____ produces an optimum amount of sediment with the least chance of damaging the elements
5 minutes
400 RCF
A uniform amount of urine and sediment should remain in the tube after decantation, a volume of ___ and ___ are frequently used
0.5 mL and 1.0 mL
Technical Tip: Commercial Systems are available that have tubes designed for decanting and provide a constant volume for suspension
Yehey! Esnupi!
Technical Tip: Recheck urine specimens for both technical and clerical errors in which the physical, chemical, and microscopic results do not correlate
WOW!
These sediment is usually present to provide a “Point-of-Reference”
Epithelial Cells
Volume of Sediment Examined
When using the conventional glass-slide method, the recommended volume is ___ covered by a 22 x 22 mm glass cover slip
20uL (0.02mL)
Microscopic examination should be performed in a consistent manner and include observation of a minimum of ___ fields under both low (10x) and high (40x) power
10 fields
Technical Tip: Use reduced light when bright-field and phase-contrast microscopy at both LPF (10x) and HPF (40x) magnifications are used for sediment examination
Thank you for the information, Strasinger!
Normal values for Addis Count
0 to 500,000 RBCs
0 to 1,800,000 WBCs and Epithelial Cells
0 to 5000 Hyaline casts
An example of a sediment element that has a refractive index very similar to urine
Hyaline casts
It is the first procedure to standardize the quantitation of formed elements in urine microscopic analysis
Addis Count
Urine Sediment Stain Characteristics
Action: Delineates structure and contrasting
colors of the nucleus and cytoplasm
Function: Identifies WBCs, epithelial cells, and casts
Sternheimer-Malbin Stain
Urine Sediment Stain Characteristics
Action: Enhances nuclear detail
Function: Differentiates WBCs from RTE cells
Toluidine blue
Urine Sediment Stain Characteristics
Action: Lyses RBCs and enhances nuclei of
WBCs
Function: Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals
2% acetic acid
Urine Sediment Stain Characteristics
Action: Stain triglycerides and neutral fats orange-red; do not stain cholesterol
Function: Identify free fat droplets and lipid containing cells and casts
Lipid stains: Oil Red O and Sudan III
Urine Sediment Stain Characteristics
Action: Stains structures containing iron
Function: Identifies yellow-brown granules of hemosiderin in cells and casts
Prussian blue stain