Deck 6: Specimen Collection, processing, and Other Preanalytical Variables

Question 1

Which one of the following analytes shows no difference in composition between a serum and a plasma specimen?

A) Lactate dehydrogenase
B) Potassium
C) Cholesterol
D) Total protein

Answer 1

Cholesterol

Question 2

When a coagulated blood sample is separated by centrifugation,the liquid component is separated from the cells.This "serum" is the:

A) liquid component with all clotting factors present in it.
B) liquid component with no clotting factors in it.
C) unclotted cellular component.
D) clot.

Answer 2

liquid component with no clotting factors in it.

Question 3

When collecting a timed urine specimen for laboratory analysis:

A) all of the urine must be collected at once into one large container instead of using smaller separate containers that are emptied into the large container.
B) the container used for collection must be maintained at room temperature throughout the entire collection period.
C) it is acceptable and best practice to collect the urine into one container containing two different mixed preservatives if more than one test is ordered.
D) the individual's bladder must be emptied first at the beginning of the time of collection,and this urine is discarded.

Answer 3

the individual's bladder must be emptied first at the beginning of the time of collection,and this urine is discarded.

Question 4

Arthrocentesis is a technique used to collect:

A) pleural fluid.
B) blood.
C) synovial fluid.
D) amniotic fluid.

Question 5

Using each answer only once, match the color of the evacuated blood collection tube stopper with the additive in that tube.
Acid citrate dextrose

A)Yellow
B)Lavender
C)Gray
D)Green

Question 6

Which one of the following anticoagulants is considered unacceptable for a blood sample that will be used for DNA amplification in the polymerase chain reaction?

A) Heparin
B) EDTA
C) Iodoacetate
D) Acid citrate dextrose

Question 7

A skin puncture of an individual's finger is ordered for hematocrit analysis and is to be collected into a capillary tube.It is cold in the phlebotomy area,and the phlebotomist notices that the individual appears cold and pale.What should the phlebotomist do to stimulate blood circulation to the finger so an acceptable fingerstick specimen will be obtained?

A) Slap the individual's hand to warm it up.
B) Tie a tourniquet around the individual's finger.
C) Warm the finger for 3 minutes using a warming device.
D) Massage the finger and hand.

Question 8

An individual has several laboratory tests ordered and is having blood collected.After applying the tourniquet,the phlebotomist has to answer the phone and write down a message,leaving the tourniquet in place for approximately 3 minutes.How will this affect this individual's serum composition of bilirubin?

A) It will be increased.
B) It will be decreased
C) It will not be affected.

Question 9

Using each answer only once, match the color of the evacuated blood collection tube stopper with the additive in that tube.
EDTA

A)Yellow
B)Lavender
C)Gray
D)Green

Question 10

The best additive in a collection tube for enhancing the vitality and recovery of white blood cells for isolation of genomic DNA is:

A) sodium citrate.
B) heparin.
C) oxalate.
D) acid citrate dextrose.

Question 11

Hemolysis will cause potassium _____ when analyzed.

A) and lactate dehydrogenase (LD)values to appear increased
B) value to appear increased and LD value to appear decreased
C) value to appear decreased and LD value to appear increased
D) and LD values to appear decreased

Question 12

An example of a preanalytical error would be:

A) mislabeling a tube of blood with an incorrect name.
B) using expired reagents in an analysis.
C) sending the test results to the incorrect physician.
D) failing to run controls with unknown samples.

Question 13

Using each answer only once, match the color of the evacuated blood collection tube stopper with the additive in that tube.
Heparin

A)Yellow
B)Lavender
C)Gray
D)Green

Question 14

An example of an uncontrollable preanalytical variable would be:

A) improper specimen collection.
B) preanalytical errors.
C) prolonged bed rest.
D) an individual's age.

Question 15

An amniotic fluid specimen for bilirubin analysis is received in the laboratory in a clear plastic collection tube.How will this affect the results of the bilirubin analysis?

A) There will be no effect on the bilirubin analysis results,because this specimen is properly collected.
B) Because the tube is not darkened,light will cause the bilirubin to be photo-degraded and the results will be falsely decreased.
C) Because there is no additive in the tube,the amniotic fluid cells will hemolyze,leading to a false increase in bilirubin.
D) Because the tube is made of plastic,the amniotic fluid will clot,and no analysis can be performed on a clotted sample.

Question 16

The type of urine specimen that is best for detection of abnormal amounts of certain analytes such as chorionic gonadotropin for pregnancy testing is a:

A) random and untimed specimen.
B) 24-hour collection.
C) clean,early morning,fasting specimen.
D) catheter specimen.

Question 17

The best use of a saliva specimen would be for which one of the following analyses?

A) Measurement of blood group substances to determine secretor status and genotype
B) Determination of whether the specimen is an effusion or an exudate
C) Early gestational age diagnosis of inherited genetic disorders
D) Characterization of the type of arthritis present in an individual

Question 18

A blood collection tube containing a specific amount of additive is only half filled with blood instead of being completely filled.Will this collection affect laboratory test results?

A) There will be no effect on the results because the additive is "calibrated" for any amount of blood in the tube.
B) There will be a significant effect on the test results because the additive must be mixed with a full tube of blood to achieve its appropriate effect.

Question 19

An individual has several laboratory tests ordered and is having blood collected.After applying the tourniquet,the phlebotomist has to answer the phone and write down a message,leaving the tourniquet in place for approximately 3 minutes.How will this affect this individual's serum composition of total protein and potassium?

A) Both will be increased.
B) Total protein will be increased and potassium will be decreased.
C) Total protein will be decreased and potassium will be increased.
D) Both will be decreased.

Question 20

As an anticoagulant,heparin acts to:

A) chelate calcium.
B) inhibit platelet aggregation.
C) antagonize vitamin K.
D) activate antithrombin.

Question 21

Using each answer only once, match the color of the evacuated blood collection tube stopper with the additive in that tube.
Glycolytic inhibitor

A)Yellow
B)Lavender
C)Gray
D)Green