CRYSTAL IDENTIFICATION Flashcards
Causes of crystal formation: (4)
a. Metabolic disorders
b. Decreased renal excretion that produces increased blood levels of crystallizing chemicals
c. Degeneration of cartilage and bones
d. Injection of medications (corticosteroid)
T/F. Both MSU and CPPD crystals are reported as being located extracellularly and intracellularly (within neutrophils); therefore, fluid must be examined before WBC disintegration.
TRUE
____ crystals are usually located within vacuoles of the neutrophils while _____crystals lyse phagosome membranes and therefore do not appear in vacuoles
CPPD; MSU
Crystals may be observed in _______
Wright-stained smear
detects the presence or absence of birefringence
Polarizing microscope
confirms the type of birefringence (positive or negative)
Compensated Polarizing Microscope
Parallel- Negative Birefringence
Yellow
Perpendicular- Positive Birefringence
Blue
Control slide for the polarization properties of MSU (monosodium urates) can be prepared using _______________
betamethasone acetate corticosteroid
Monosodium urate
a. Shape
b. Compensated Polarized Light
c. Significance
a. Fine needles
b. Negative birefringence
c. Gout
Calcium Pyrophosphate
a. Shape
b. Compensated Polarized Light
c. Significance
a. Rhombic squares, rods
b. Positive birefringence
c. Pseudogout or chondrocalcinosis
Cholesterol
a. Shape
b. Compensated Polarized Light
c. Significance
a. Notched, rhombic plates
b. Negative birefringence
c. Extracellular, chronic arthritis condition such as Rheumatoid arthritis
Corticosteroid
a. Shape
b. Compensated Polarized Light
c. Significance
a. Flat, variables-shaped plates
b. Positive & Negative Birefringence
c. Injections
Calcium oxalate
a. Shape
b. Compensated Polarized Light
c. Significance
a. Envelopes
b. Negative birefringence
c. Renal dialysis
Apatite (Calcium Phosphate)
a. Shape
b. Compensated Polarized Light
c. Significance
a. Small particles; requires
b. No birefringence electron microscopy
c. Osteoarthritis
