Sample Collection and Handling

Question 1

Which color of tube(s) are used for most chemistry tests? Whole Blood, Plasma, or Serum?

Answer 1

Red Top: Serum without a gel separator
Gold Top: Serum with a gel separator

Question 2

Which of the following is BEST used for chemistry testing?
a. Oxalate
b. Citrate
c. Heparin
d. EDTA

Answer 2

c. Heparin

Question 3

When do we use heparin? What should be done after the specimen is drawn?

Answer 3

Used for Ammonia, Blood gases, and Lactic acid testing; Put on ice

Question 4

Which test uses sodium fluoride and why?

Answer 4

Glucose; inhibits glycolysis

Question 5

Why do we not use sodium fluoride tubes for BUN?

Answer 5

Inhibits urease; falsely decreases value

Question 6

What should be done if the acid phosphatase (ACD) test cannot be run immediately? (3)

Answer 6

1. Freeze
2. Add disodium citrate monohydrate to stabilize
3. Acidify to 5.4 with acetic acid

Question 7

Why is EDTA not used for sodium (Na) or potassium (K)? How does it affect their result?

Answer 7

EDTA contains Na and K; False increase in values

Question 8

Why is EDTA not used for calcium (Ca)? How does it affect their result?

Answer 8

EDTA will chelate Ca; False decrease in values

Question 9

Which results will increase due to the sample being hemolyzed?

Answer 9

K = Potassium (K)
L = Lactate Dehydrogenase (LD)
A = Aldose (ALD) & Acid Phosphatase (ACD)
M = Magnesium (Mg)
P = Phosphate (PO4)
Hem = Hemoglobin (Hgb)

Question 10

What happens when the hemoglobin value is increased?

Answer 10

1. Protein Electrophoresis –> May show EXTRA bands
2. Ferrous (Fe2+) increases