Changes in Unpreserved Urine at Room
Temperature >2 hr
Urinalysis and Body
Fluids Review 489
CHANGE CAUSE
Turbidity ↑ Multiplication of bacteria, precipitation of amorphous crystals
pH ↑ Conversion of urea to ammonia by bacteria
Glucose ↓ Metabolism by bacteria
Ketones ↓ Volatilization of acetone, breakdown of acetoacetate by bacteria
Bilirubin ↓ Oxidation to biliverdin
Urobilinogen ↓ Oxidation to urobilin
WBCs, RBCs, casts ↓ Lysis in dilute or alkaline urine