Measurement of the concentration of potassium in serum is called?

• A. PHLEBOTOMY
• B. Potassium test
• C. Paracentesis
• D. PKU test

Answer: (B)

Measuring a specific chemical in the blood is called a test for that chemical. When you assess how much potassium is in serum, you’re performing a potassium test to determine the serum potassium concentration. This helps detect imbalances like hyperkalemia or hypokalemia and guide treatment. The other options describe procedures rather than the measurement itself: phlebotomy is drawing blood, paracentesis is removing fluid from the abdominal cavity, and the PKU test screens newborns for phenylketonuria. In practice, potassium is often checked as part of an electrolyte panel or CMP, but the direct measurement is called a potassium test.