Chemical preservatives Adv and Disadv

Question 1

What does a use of chemical preservatives allow?

Answer 1

(a) Transport of urine from home to laboratory

(b) Shipment of urine across the country.

Question 2

Freezing advantage and disadvantage?

Answer 2

• For specimen transport

* May destroy formed elements

Question 3

Toulene advantages and disadvantages?

Answer 3

• Preserves acetone, diacetic acid and proteins by floating on top of urine (airtight seal)
• Flammable, difficult to separate from specimen

Question 4

Pros/Cons of thymol?

Answer 4

• Inhibits bacteria/fungus

* False positive for protein

Question 5

Pros/Cons of chrloroform?

Answer 5

• Preserves urine aldosterone levels

* Settles to bottom of containers

Question 6

Pros/cons of Formaldehyde?

Answer 6

• Preserves urinary sediment/cells.

* Interferes with glucose elevation

Question 7

Pros/Cons of Hydrogen Chloride?

Answer 7

• Stabilizes steroids

* Hazardous liquid & fumes. Formed elements are destroyed

Question 8

Pros/cons of boric acid?

Answer 8

• Preserves chemical and formed elements

* Uric acid may precipitate

Question 9

Pros/cons of preservation tablet?

Answer 9

• Preserves urine for dipstick chemical analysis and sediment evaluation, if transport is necessary
• Unsuitable for sodium, potassium and hormone analysis