Final answer:
Cholesterol levels are measured using serum or plasma in laboratory tests, as they involve analyses of substances dissolved in the liquid component of blood, unlike tests for bleeding time, hemoglobin, platelets, and erythrocytes. The correct option is E.
Step-by-step explanation:
The use of serum or plasma is necessary for laboratory tests that involve analyses of substances within the blood that are not related to the cells themselves but rather to the liquid component of blood.
While elements such as bleeding time, hemoglobin, platelets, and erythrocytes are related to the cellular or coagulation functions of the blood, the measurement of cholesterol levels is typically performed using serum or plasma.
This is because cholesterol is a substance that is dissolved in the blood serum or plasma, alongside other blood lipids, and is not found within the blood cells.
Serum is essentially the component of plasma from which clotting factors have been removed, which allows for the measurement of various metabolites, enzymes, proteins, electrolytes, and antibodies.
Therefore, for the laboratory test mentioned in the question, cholesterol would be the correct answer as it requires the use of serum or plasma for measurement. The correct option is E.