CMLA Urinalysis 5 — Questions and Answers
Question 1: What is the maximum time a urine specimen should be stored at room temperature before analysis?
- 30 minutes
- 2 hours (Correct answer)
- 6 hours
- 24 hours
Correct answer: 2 hours
Urine should be analyzed within 2 hours of collection at room temperature to prevent bacterial growth and cellular degeneration.
Question 2: Triple phosphate crystals in urine are also known as:
- Coffin-lid crystals (Correct answer)
- Envelope crystals
- Dumbbell crystals
- Needle crystals
Correct answer: Coffin-lid crystals
Triple phosphate (struvite) crystals have a characteristic coffin-lid or prism shape and are found in alkaline urine.
Question 3: Which urine test result is considered a CRITICAL finding requiring immediate physician notification?
- Trace protein
- Glucose 1+
- Positive glucose with large ketones in a known diabetic (Correct answer)
- Specific gravity 1.020
Correct answer: Positive glucose with large ketones in a known diabetic
Large ketones with positive glucose in a diabetic may indicate diabetic ketoacidosis (DKA), a life-threatening emergency requiring immediate notification.
Question 4: What does a cloudy or turbid urine appearance most commonly indicate?
- Hemoglobinuria
- Presence of cells, bacteria, or crystals (Correct answer)
- Bilirubin
- Myoglobinuria
Correct answer: Presence of cells, bacteria, or crystals
Turbidity in urine is most commonly caused by white blood cells, red blood cells, bacteria, or precipitated crystals.
Question 5: In a midstream clean-catch urine, how many squamous epithelial cells per low-power field indicate probable contamination?
- 1–2
- 3–5
- More than 5 (Correct answer)
- Any number
Correct answer: More than 5
More than 5 squamous epithelial cells per low-power field suggests significant vaginal or skin contamination of the specimen.
Question 6: Phenylketonuria (PKU) classically produces which characteristic urine odor?
- Fruity (acetone)
- Musty or mousy (Correct answer)
- Cabbage-like
- Maple syrup
Correct answer: Musty or mousy
PKU causes accumulation of phenylalanine metabolites (phenylpyruvic acid) giving urine a musty or mousy odor.
Question 7: Which stain is used to identify fat droplets (lipids) in urine sediment?
- Gram stain
- Sudan III or Oil Red O stain (Correct answer)
- Wright's stain
- Periodic acid-Schiff (PAS) stain
Correct answer: Sudan III or Oil Red O stain
Sudan III or Oil Red O stains lipid droplets orange-red, helping identify oval fat bodies and fatty casts in urine.
CMLA Urinalysis 5
What is the maximum time a urine specimen should be stored at room temperature before analysis?