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1.3: Sources and Control of Preanalytical Variation

  • Page ID
    38583
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    Use the following key to answer questions 1 through 4.

    1. 1,2, and 3 are correct
    2. 1 and 3 are correct
    3. 2 and 4 are correct
    4. only 4 is correct
    5. all are correct
    1. Moderate levels of hemoglobin can cause methodological interference in which of the following analytical procedures?
      1. cholesterol
      2. albumin
      3. triglycerides
      4. iron
    2. The information on a chain of custody document includes:
      1. subject name
      2. person sending specimen
      3. person receiving specimen
      4. condition of seals
    3. The purpose of a chain of custody document is to:
      1. ensure that no tampering of the sample occurred
      2. ensure that the specimen is derived from the appropriate individual
      3. ensure that the reported results are correct for
        the appropriate individual
      4. ensure that quality control was performed
    4. Which of the following patient variables can affect measured analyte concentrations?
      1. diurnal variation
      2. posture
      3. stasis
      4. height
    5. All of the following are higher in the morning than the afternoon or evening (in persons with a normal wake:sleep cycle) EXCEPT:
      1. ACTH
      2. Cortisol
      3. Iron
      4. Prolactin
      5. Renin/aldosterone
    6. Which of the following is typically decreased after meals?
      1. Chloride
      2. Gastrin
      3. Growth hormone
      4. Insulin
      5. Triglycerides
    7. EDTA contamination will decrease all of the following analytes EXCEPT:
      1. Alkaline phosphatase
      2. Calcium (spectrophotometric methods)
      3. Creatine kinase
      4. Magnesium (spectrophotometric methods)
      5. Potassium
    8. The mechanism of interference in hemolyzed samples is correctly matched with the test name in all of the following combinations EXCEPT:
      1. Bilirubin – release from red blood cells
      2. Cholesterol – interference in assay
      3. Creatine kinase – interference in assay
      4. Lactate dehydrogenase – release from red blood cells
      5. Magnesium – release from red blood cells.
    9. Appropriate tests to use for delta checks, since they show low intra-individual variation, little day to day variation, but higher inter-individual variation, include:
      1. Alkaline phosphatase
      2. Creatine kinase
      3. Glucose
      4. Lactate dehydrogenase
      5. Phosphate
    10. The percent intraindividual variation is highest for:
      1. Albumin
      2. Calcium
      3. Creatinine
      4. Sodium
      5. Triglycerides
    11. Regular aerobic exercise is associated with:
      1. Decreased glucose
      2. Decreased bilirubin
      3. Decreased creatine kinase
      4. Increased aspartate aminotransferase
      5. Increased alanine aminotransferase
    12. Short term, intensive exercise, such as running a marathon, is associated with:
      1. Decreased potassium
      2. Decreased uric acid
      3. Decreased glucose
      4. Decreased creatine kinase
      5. Increased phosphate
    13. All of the following increase after a meal EXCEPT:
      1. Glucose
      2. Insulin
      3. Iron
      4. Potassium
      5. Triglycerides
    14. Stress is associated with which of the following?
      1. Decreased cortisol
      2. Decreased catecholamines
      3. Decreased cholesterol
      4. Increased high density lipoprotein cholesterol
      5. Increased TSH
    15. All of the following are increased by upright posture EXCEPT:
      1. Albumin
      2. Calcium (total)
      3. Cholesterol
      4. Iron
      5. Potassium
    16. Which of the following statements regarding differences between arterial and venous blood is INCORRECT?
      1. Arterial blood has higher concentrations of metabolites extracted by tissue, such as oxygen and glucose.
      2. Arterial blood has lower concentrations of waste products, such as carbon dioxide and ammonia.
      3. Capillary blood is more similar to arterial than to venous blood.
      4. The difference between arterial and venous blood is increased with poor tissue perfusion.
      5. The difference between arterial and venous blood glucose is similar in fasting and postprandial collections.
    Answer
    1. b (p. 73)
    2. e (p. 73-74)
    3. a (p. 74)
    4. a (p. 66-68)
    5. d (p. 69)
    6. a (p. 69)
    7. e (p. 71)
    8. a (p. 73)
    9. a (p. 80)
    10. e (p. 67)
    11. c (p. 67-68)
    12. c (p. 67)
    13. d (p. 69)
    14. c (p. 68)
    15. d (p. 68)
    16. a (p. 70)

    This page titled 1.3: Sources and Control of Preanalytical Variation is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Lawrence Kaplan & Amadeo Pesce.

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