Preservation Flashcards
specimen should be delivered to the laboratory promptly and tested within
2 HRS
If it cannot be delivered and tested within 2 hours it should be
Refrigerated
Added with preservatives
Physical Preservation
Refrigeration (2-8 deg)
Freezer
Chemical Preservation
a. formalin
b. Thymol
c. Boric acid
d. Toluene/Tuluol
e. Sodium fluoride/Benzoic acid
F. Phenol
g. HCl
h. H2SO4
i. Saccamano’s fixative
Chemical Preservation:
Addis count
Formalin
Chemical Preservation:
Culture
Boric Acid
Chemical Preservation:
Glucose
Sodium fluoride
benzoic acid
Chemical Preservation:
Catecholamines
HCl
Chemical Preservation:
Cytology
Saccamano’s fixative
URINE PRESERVATIVES:
Advantage:
Does not interfere with chemical test
Disadvantage:
Precipitates amorphous urates and phosphates
Additional Info:
Prevents bacterial growth in 24 hrs
Refrigeration
URINE PRESERVATIVES:
Advantage:
Glucose and Sediments
Disadvantage:
interferes acid precipitation (Protein)
Other:
Thymol
URINE PRESERVATIVES:
Advantage:
Proteins and formed elements
Disadvantage:
precipitate crystals when used in large amounts
Other:
maintains pH @6.0
Boric Acid
URINE PRESERVATIVES:
Advantage:
Excellent sediment preservative
Disadvantage:
-acts as reducing agent
- Interfere:
glucose
blood
leukocyte esterase
copper reduction
Other:
rinse container to preserve cells and cast
Formalin
URINE PRESERVATIVES:
Advantage:
does not interfere with routine tests
Disadvantage:
floats on surface and clings to pipet
Other:
Preserves ketones, proteins, reducing substances
Toluene
URINE PRESERVATIVES:
Advantage:
- prevents glycolysis
- drug analyses
Disadvantage:
- Inhibits reagent strip
Glucose
Blood
Leukocytes
Other:
Sodium Fluoride
This may used instead of sodium fluoride for reagent strip
Sodium benzoate
URINE PRESERVATIVES:
Advantage:
does not interfere with routine test
Disadvantage:
odor change
Other:
use 1 drop per ounce of specimen
Phenol
URINE PRESERVATIVES:
Advantage:
convenient when refrigeration is not possible
Disadvantage:
may contain 1 or more preservatives
Other:
Commercial preservatives
URINE PRESERVATIVES:
Advantage:
contains collection cup, C&S preservative, UA tube
Urine Collection Kit
URINE PRESERVATIVES:
Advantage:
- sample stable at room temperature @ 48hrs
- preserves bacteria
Other:
uses Boric acid
may not be used UA
Gray C&S Tube
URINE PRESERVATIVES:
Advantage:
used on automated instruments
Disadvantage:
must refrigerate within 2 hrs
Other:
Round/Conical bottom
Yellow plain UA
URINE PRESERVATIVES:
Advantage:
stable for 72 hours @Room temperature
Disadvantage:
If left @RT and light; decreased in Bilirubin and Urobilinogen
Other:
Preservative is SODIUM PROPIONATE
Cherry Red/Yellow top tube
URINE PRESERVATIVES:
Advantage:
Cellular elements
Cytology studies
Saccamano’s fixatives
