CLS Clinical Chemistry

Question 1

Which specimen is preferred for most clinical chemistry tests to avoid interference from cellular components?

Accepted Answer

Serum or plasma separated from cells

Answer

Serum or plasma is preferred for most clinical chemistry tests because cellular components can interfere with analyte measurement and enzymatic reactions.

Question 2

A patient's serum glucose is measured at 350 mg/dL. Which method is considered the reference method for glucose measurement in clinical laboratories?

Accepted Answer

Hexokinase method

Answer

The hexokinase method is considered the reference method for glucose measurement due to its high specificity and accuracy.

Question 3

Which enzyme is most cardiac-specific and is considered the gold standard biomarker for myocardial infarction diagnosis?

Accepted Answer

Cardiac troponin I or T

Answer

Cardiac troponin I and T are the gold standard biomarkers for myocardial infarction due to their high cardiac specificity and sensitivity.

Question 4

The normal anion gap range is approximately 8-12 mEq/L. Which formula correctly calculates the anion gap?

Accepted Answer

Na+ - (Cl- + HCO3-)

Answer

The anion gap is calculated as Na+ minus the sum of Cl- and HCO3-, representing unmeasured anions in plasma.

Question 5

Which lipid fraction is inversely associated with cardiovascular disease risk and is often called 'good cholesterol'?

Accepted Answer

HDL cholesterol

Answer

HDL cholesterol is inversely associated with cardiovascular risk because it facilitates reverse cholesterol transport from peripheral tissues to the liver.

CLS - Certified Laboratory Professional Practice Test

CLS - Certified Laboratory Professional Practice Test

CLS Clinical Chemistry