Microscopic Examination of Urine Flashcards
Identify the microscopic technique:
for routine urinalysis
bright-field
Identify the microscopic technique:
for elements with low refractive index
(hyaline casts, mucus threads)
phase-contrast
Identify the microscopic technique:
ID of OFB, fatty casts, and crystals
polarizing
Identify the microscopic technique:
ID of Treponema pallidum
dark-field
Identify the microscopic technique:
3D-microscopy
interference-contrast
Identify stain:
action: Delineates structure and contrasting colors of the nucleus and cytoplasm
function: Identifies WBCs, epithelial cells, and casts
Sternheimer-Malbin
Identify stain:
action: Enhances nuclear detail
function: Differentiates WBCs from RTE cells
Toluidine blue
Identify stain:
action: Lyses RBCs and enhances nuclei of WBCs
function: Distinguishes RBCs from WBCs, yeast, oil droplets, and crystals
2% acetic acid
Identify stain:
action: Stain triglycerides and neutral fats orange-red
function: Identify free fat droplets and lipid-containing cells and casts
do not stain cholesterol
Lipid stains
(Oil Red O and Sudan III)
Identify stain:
action: Differentiates gram-positive and gram- negative bacteria
function: Identifies bacterial casts
gram stain
Identify stain:
action: Methylene blue and eosin Y stains eosinophilic granules
function: Identifies urinary eosinophils
Hansel stain
Identify stain:
action: Stains structures containing iron
function: Identifies yellow-brown granules of hemosiderin in cells and casts
Prussian blue stain
settings for centrifugation of microscopic specimens
5mins at 400 RCF
What is the minimum of fields to observe under LPO and HPO?
10 fields
Identify the urine sediment:
- biconcave disk
- ghost cells
sig: glomerular damage, infection, trauma, tumors, renal calculi
RBCs
diluted urine: swell/burst
concentrated urine: crenated/shrink
Identify the urine sediment:
glitter cells with brownian movement
sig: cystitis, pyelonephritis, tumors, renal calculi
neutrophils
Identify the urine sediment:
- largest cell sediment
- clue cells
no clinical significance
squamous epithelial cells
(from linings of vagina, female + male lower urethra)
Identify the urine sediment:
- from linings of renal pelvis, ureters, bladder, upper urethra
- in small numbers
sig: may form syncytia (clumps)
Transitional Epithelial cells
Identify the urine sediment:
- most clinically significant
- indicative of necrosis of renal tubules
sig: tubular necrosis, toxins, viral infections, and renal rejection
Renal tubular epithelial cell
Identify the urine sediment:
- RTE cell containing fat droplets
- Maltese cross appearance with polarized light
sig: nephrotic syndrome
Oval Fat Bodies
Identify the urine sediment:
- urine pH>8
- significant of UTI if accompanied with WBCs
Bacteria
Identify the urine sediment:
- most frequent parasite in urine
- flagellate w/ half undulating membrane
- motility: rapid, jerky, nondirectional
resembles WBC if not moving
T. vaginalis
Identify the urine sediment:
- toxic to urine
- female vaginal contaminants
spermatozoa
Identify the urine sediment:
a protein material that is transparent and thread-like (ribbon)
no clinical significance
mucus
mistaken for hyaline casts
What is the major constituent of mucus and urine casts?
uromodulin
Where does urine casts are formed?
DCT and collecting ducts
Where can you find urine casts during microscopic examination?
edges of cover slip
Identify the urine cast:
- most frequently seen but least significant
- pink in Steinheimer-Malbin
↑ with stress, exercise, renal disease, congestive heart failure
Hyaline casts
Identify the urine cast:
- most fragile
- damage to the glomerulus
Sig: acute glomerulonephritis
RBC casts
Identify the urine cast:
- infection/inflammation within nephron
sig: pyelonephritis
WBC cast
Identify the urine cast:
- urinary stasis
- fragmented with jagged ends
waxy cast
Identify the urine cast:
- nephrotic syndrome
- contain lipid droplets
fatty casts
Identify the urine cast:
- renal failure casts
- advanced renal disease
broad casts
Identify the urinary crystal:
- pH: acid or neutral (normal)
- rosettes + wedges
sig: gout
uric acid
Identify the urinary crystal:
- pH: acid or neutral (normal)
- color: brick-dust/yellow brown
Form pink precipitate
amorphous urates
Identify the urinary crystal:
- pH: acid/neutral (normal)
- color: colorless (envelopes, dumbell, and ovoid)
Most common constituent of renal calculi
calcium oxalate
Identify the urinary crystal:
- pH: normal alkaline
- form white precipitate
amorphous phosphates
Identify the urinary crystal:
coffin-lid appearance
normal alkaline
triple phosphate
Identify the urinary crystal:
thorny apples
normal alkaline; old specimens
ammonium biurate
Identify the urinary crystal:
dumbbells
normal alkaline
calcium carbonate
Identify the urinary crystal:
- pH: normal alkaline
- needles
calcium phosphate
Identify the urinary crystal:
- yellow, oily-looking
- radial and concentric striations
- seen with tyrosine
liver disease
leucine
Identify the urinary crystal:
fine yellow needles in sheaves
liver disease
tyrosine
Identify the urinary crystal:
hexagonal
doesn’t polarize light
cystine
Identify the urinary crystal:
notched-out corners/ “stairs”
bifringent
cholesterol
