Ch. 3 - Urine Preservatives & Types of Specimens (General) Flashcards
What urine preservative does not interfere with chemical tests and prevents bacterial growth?
Refrigeration
What are the disadvantages of refrigeration?
Raises specific gravity by hydrometer
Precipitates amorphous phosphates and urates
What urine preservative preserves glucose and sediments well?
Thymol
What are the disadvantages of using thymol as a preservative?
It interferes with acid precipitation tests for protein
What urine preservative preserves protein and formed elements well and does not interfere with routine analyses other than pH? It keeps pH at about 6.0
Boric acid
The disadvantage of this urine preservative is that it may precipitate crystals when used in large amounts and can interfere with drugs and hormone analyses
Boric acid
What urine preservative is an excellent sediment preservative?
Formalin (formaldehyde)
The disadvantage of this urine preservative is that it acts as a reducing agent, interfering with chemical tests for glucose, blood, leukocyte esterase, and copper reduction.
Formalin (formaldehyde)
What urine preservatives do not interfere with routine tests?
Toluene
Phenol
The disadvantage of this urine preservative is that it floats on surface of specimens and clings to pipettes and testing materials.
Toluene
What urine preservative prevents glycolysis and is a good preservative for drug analysis?
Sodium flouride
The disadvantage of this urine preservative is that it inhibits reagent strip tests for glucose, blood, and leukocytes
Sodium flouride
It is a urine preservative that is convenient when refrigeration is not possible and has controlled concentration to minimize interference.
Commercial preservative tablets
The disadvantage of this urine preservative is that it may contain one or more of the preservatives including sodium flouride
Commercial preservative tablets
The disadvantage of this urine preservative is that it causes on odor change.
Phenol
It is a urine preservative that contains collection cup, C&S preservative tube or UA tube
Urine Collection Kit^6 (Becton Dickinson, Rutherford, NJ)
It is a urine preservative that has no noted disadvantages
Urine Collection Kit^6 (Becton Dickinson, Rutherford, NJ)
Saccomanno Fixative
It is a urine preservative that preserves bacteria and has the sample stable at room temperature for 48 hrs.
Gray C&S tube
The disadvantage of this urine preservative is that it decreases pH. It should not be used when urine is below minimum fill line.
Gray C&S tube
It is a urine preservative that is used on automated instruments
Yellow plain UA tube
The disadvantage of this urine preservative is that it must be refrigerate within 2 hrs
Yellow plain UA tube
It is a urine preservative that is stable for 72 hrs at RT and is instrument-compatible
Cherry red/yellow top tube
The disadvantage of this urine preservative is that it may decrease bilirubin and urobilinogen if specimen is exposed to light and left at RT
Cherry red/yellow top tube
It is a urine preservative that preserves cellular elements and is used for cytology studies
Saccomanno Fixative
