URINE PRESERVATIVES

Question 1

The easiest and most common urine preservative

Answer 1

Refrigeration (2-8’C)

Question 2

Advantage:

Does not interfere with chemical tests

Answer 2

Refrigeration (2-8’C)

Question 3

Disadvantage:

PRECIPITATES AMORPHOUS CRYSTALS
Raises specific gravity by hydrometer

Answer 3

Refrigeration (2-8’C)

Question 4

Prevents bacterial growth for 24 hours

Answer 4

Refrigeration (2-8’C)

Question 5

Advantage:

Preserves glucose and sediments well

Answer 5

Thymol

Question 6

Disadvantage:

Interfere with acid precipitation test for protein

Answer 6

Thymol

Question 7

Advantage:

*Preserves protein and formed elements well
*Does not interfere with routine analysis other than pH
*Prevents bacterial growth and metabolism

Answer 7

Boric acid

Question 8

Disadvantage:

May precipitate crystals when used in large amounts and interferes with drug and hormone analyses

Answer 8

Boric acid

Question 9

Keeps pH at 6.0

Answer 9

Boric acid

Question 10

Boric acid is bacteriostatic at…

Answer 10

18g/L

Question 11

Advantage:

EXCELLENT SEDIMENT PRESERVATIVE

Answer 11

Formalin

Question 12

Disadvantage:

*Acts as reducing agent
*Interfere with chemical tests for glucose, blood, leukocyte esterase, and copper reduction
*False-negative reagent strip tests for blood and urobilinogen

Answer 12

Formalin

Question 13

Can also be used for cytology (Brunzel)

Answer 13

Formalin

Question 14

Advantage:

Does not interfere with routine test

Answer 14

Toluene
Phenol

Question 15

Disadvantage:

Floats on surface of specimens and clings to pipette and testing materials

Answer 15

Toluene

Question 16

Advantage:

PREVENTS GLYCOLYSIS
GOOD FOR DRUG ANALYSIS

Answer 16

Sodium Fluoride

Question 17

Disadvantage:

Inhibits reagent strip tests for glucose, blood, and leukocytes

Answer 17

Sodium Fluoride

Question 18

May use ________ instead of fluoride for reagent strip testing

Answer 18

sodium benzoate

Question 19

Disadvantage:

Causes an odor change

Answer 19

Phenol

Question 20

Use 1 drop per ounce of specimen

Answer 20

Phenol

Question 21

Advantage:

Preserves bacteria
Sample stable at RT for 48hr

Answer 21

Gray C and S tube

Question 22

Disadvantage:

Decreases pH; do not use if urine is below minimum fill line

Answer 22

Gray C and S tube

Question 23

Gray C and S tube preservative

Answer 23

boric acid

Question 24

Advantage:

Stable for 72 hours

Answer 24

Cherry red/ yellow top tube

Question 25

Disadvantage: Bilirubin and urobilinogen may be decreased if specimen is exposed to light and left at RT

Answer 25

Cherry red/ yellow top tube

Question 26

Cherry red/ yellow top tube preservative

Answer 26

sodium propionate

Question 27

Advantage: For automated instruments

Answer 27

Yellow Plain UA

Question 28

Disadvantage: Must refrigerate within 2 hours

Answer 28

Yellow Plain UA

Question 29

Round or conical bottom

Answer 29

Yellow Plain UA

Question 30

(Ethanol + Carbowax)

Answer 30

Saccomanno fixative

Question 31

Advantage: Preserves cellular elements

Answer 31

Saccomanno fixative

Question 32

Used for CYTOLOGICAL EXAMINATION

Answer 32

Saccomanno fixative

Question 33

Advantage: Inexpensive Stabilizes porphyrins, porphobilinogen, etc.

Answer 33

Sodium carbonate

Question 34

Disadvantage: Unacceptable for urinalysis testing

Answer 34

Sodium carbonate

Question 35

For quantitative analysis of porphyrins, porphobilinogen, etc.

Answer 35

Sodium carbonate