NHA Phlebotomy Certification Practice Exam

Which of the following is not one of the three types of blood samples?

1. Whole blood

2. Plasma

3. Serum

4. Iron

The correct answer is: Iron

The three types of blood samples commonly used in laboratory analyses are whole blood, plasma, and serum. Whole blood includes all components of blood, such as red blood cells, white blood cells, platelets, and plasma. Plasma is the liquid component that remains when the blood cells are removed, containing water, electrolytes, proteins, hormones, and waste products. Serum is the portion of the blood that remains after coagulation, which means it does not contain fibrinogen or other clotting factors. Iron, while an important element in the body and crucial for processes such as hemoglobin formation, is not a type of blood sample. Instead, it is a nutrient found in blood and can be measured as part of various tests. Understanding the distinctions between these terms is essential for accurate sample collection and interpretation of laboratory results.