AMT MLS Exam Actual Practice Exam Test Bank |
Complete 450 Real Questions
This professional certification resource is a premier test bank designed for candidates
preparing for the American Medical Technologists (AMT) Medical Laboratory Scientist
(MLS) certification exam. It features a comprehensive bank of 450 realistic exam
questions accompanied by 100% verified correct answers and detailed analytical
rationales. Practicing with these target parameters ensures deep competence across
the core work domains—including Hematology, Clinical Chemistry, Blood Banking, and
Lab Safety—guaranteeing you comfortably secure the required 70 scaled passing
score on your first attempt
Section 1: General Laboratory (Questions 1–80)
1. A laboratory receives a serum specimen for potassium testing that is visibly
hemolyzed. What is the most likely effect on the potassium result, and why?
A) Falsely decreased due to potassium movement into cells
B) Falsely increased due to potassium released from RBCs
C) No significant effect because serum is used
D) Falsely decreased due to binding of potassium to hemoglobin
Answer: B
Rationale: Hemolysis releases intracellular potassium from red blood cells into the serum,
causing a falsely elevated potassium result. The intracellular concentration of potassium is
approximately 20 times higher than in serum, so even slight hemolysis can significantly
increase the measured potassium level .
,2. According to CLIA '88, which of the following is a requirement for laboratory
quality control?
A) Running controls only when a new lot of reagents is opened
B) Running at least two levels of controls each day of patient testing
C) Running controls only after instrument maintenance
D) Running controls only when patient results are abnormal
Answer: B
Rationale: CLIA '88 requires that laboratories run at least two levels of controls (e.g.,
normal and abnormal) each day of patient testing to ensure the accuracy and precision of
test results. Controls must be run at regular intervals, not just when new reagents are
opened or after maintenance .
3. A technologist is performing a manual white blood cell count using a
hemocytometer. The cells are counted in all four corner squares of the Neubauer
chamber. The total count is 200 cells. The dilution is 1:20. What is the WBC count
in cells/μL?
A) 2,000
B) 5,000
C) 10,000
D) 20,000
Answer: C
Rationale: The formula for WBC count is: (Number of cells counted × Dilution factor × 10)
/ Number of squares counted. Here, (200 × 20 × 10) / 4 = 40, = 10,000 cells/μL.
The factor of 10 converts the volume of the square (0.1 μL) to 1 μL .
4. Which of the following is the correct order of draw for venipuncture using
evacuated tube system?
,A) Yellow (SPS), Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA), Gray
(fluoride)
B) Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA), Gray (fluoride),
Yellow (SPS)
C) Red (serum), Light Blue (citrate), Green (heparin), Lavender (EDTA), Gray (fluoride),
Yellow (SPS)
D) Gray (fluoride), Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA),
Yellow (SPS)
Answer: A
Rationale: The correct order of draw is: Yellow (blood culture/SPS), Light Blue (sodium
citrate for coagulation), Red (serum), Green (heparin), Lavender (EDTA for hematology),
Gray (sodium fluoride/potassium oxalate for glucose). This order prevents cross-
contamination of additives between tubes .
5. What is spectrophotometry used for in clinical chemistry?
A) To measure the absorption of light by a chemical substance to determine its
concentration
B) To separate molecules based on size and charge
C) To measure the emission of light by excited molecules
D) To determine the pH of a solution
Answer: A
Rationale: Spectrophotometry measures the absorption of light by a chemical substance at
a specific wavelength to determine its concentration. The Beer-Lambert Law states that
absorbance is directly proportional to concentration .
6. What is the Beer-Lambert Law?
A) It states that the absorbance of light is directly proportional to the concentration of
the absorbing substance in a solution
, B) It states that the emission of light is proportional to the concentration of the
substance
C) It states that the refractive index is proportional to concentration
D) It states that the rate of reaction is proportional to concentration
Answer: A
Rationale: The Beer-Lambert Law states that the absorbance of light is directly
proportional to the concentration of the absorbing substance in a solution. This principle is
the foundation of spectrophotometric analysis .
7. What is the principle behind electrophoresis?
A) It separates molecules based on their size and charge using an electric field
B) It measures the absorption of light by molecules
C) It measures the emission of light by excited molecules
D) It separates molecules based on boiling point
Answer: A
Rationale: Electrophoresis separates molecules (e.g., proteins, DNA) based on their size and
charge using an electric field. Charged molecules migrate through a gel or medium at
different rates .
8. What is the difference between end-point and kinetic reactions in clinical
chemistry?
A) End-point reactions measure the final product after the reaction is complete, while
kinetic reactions measure the rate of change during the reaction
B) End-point reactions measure the rate of change, while kinetic reactions measure the
final product
C) Both measure the rate of change
D) Both measure the final product
Complete 450 Real Questions
This professional certification resource is a premier test bank designed for candidates
preparing for the American Medical Technologists (AMT) Medical Laboratory Scientist
(MLS) certification exam. It features a comprehensive bank of 450 realistic exam
questions accompanied by 100% verified correct answers and detailed analytical
rationales. Practicing with these target parameters ensures deep competence across
the core work domains—including Hematology, Clinical Chemistry, Blood Banking, and
Lab Safety—guaranteeing you comfortably secure the required 70 scaled passing
score on your first attempt
Section 1: General Laboratory (Questions 1–80)
1. A laboratory receives a serum specimen for potassium testing that is visibly
hemolyzed. What is the most likely effect on the potassium result, and why?
A) Falsely decreased due to potassium movement into cells
B) Falsely increased due to potassium released from RBCs
C) No significant effect because serum is used
D) Falsely decreased due to binding of potassium to hemoglobin
Answer: B
Rationale: Hemolysis releases intracellular potassium from red blood cells into the serum,
causing a falsely elevated potassium result. The intracellular concentration of potassium is
approximately 20 times higher than in serum, so even slight hemolysis can significantly
increase the measured potassium level .
,2. According to CLIA '88, which of the following is a requirement for laboratory
quality control?
A) Running controls only when a new lot of reagents is opened
B) Running at least two levels of controls each day of patient testing
C) Running controls only after instrument maintenance
D) Running controls only when patient results are abnormal
Answer: B
Rationale: CLIA '88 requires that laboratories run at least two levels of controls (e.g.,
normal and abnormal) each day of patient testing to ensure the accuracy and precision of
test results. Controls must be run at regular intervals, not just when new reagents are
opened or after maintenance .
3. A technologist is performing a manual white blood cell count using a
hemocytometer. The cells are counted in all four corner squares of the Neubauer
chamber. The total count is 200 cells. The dilution is 1:20. What is the WBC count
in cells/μL?
A) 2,000
B) 5,000
C) 10,000
D) 20,000
Answer: C
Rationale: The formula for WBC count is: (Number of cells counted × Dilution factor × 10)
/ Number of squares counted. Here, (200 × 20 × 10) / 4 = 40, = 10,000 cells/μL.
The factor of 10 converts the volume of the square (0.1 μL) to 1 μL .
4. Which of the following is the correct order of draw for venipuncture using
evacuated tube system?
,A) Yellow (SPS), Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA), Gray
(fluoride)
B) Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA), Gray (fluoride),
Yellow (SPS)
C) Red (serum), Light Blue (citrate), Green (heparin), Lavender (EDTA), Gray (fluoride),
Yellow (SPS)
D) Gray (fluoride), Light Blue (citrate), Red (serum), Green (heparin), Lavender (EDTA),
Yellow (SPS)
Answer: A
Rationale: The correct order of draw is: Yellow (blood culture/SPS), Light Blue (sodium
citrate for coagulation), Red (serum), Green (heparin), Lavender (EDTA for hematology),
Gray (sodium fluoride/potassium oxalate for glucose). This order prevents cross-
contamination of additives between tubes .
5. What is spectrophotometry used for in clinical chemistry?
A) To measure the absorption of light by a chemical substance to determine its
concentration
B) To separate molecules based on size and charge
C) To measure the emission of light by excited molecules
D) To determine the pH of a solution
Answer: A
Rationale: Spectrophotometry measures the absorption of light by a chemical substance at
a specific wavelength to determine its concentration. The Beer-Lambert Law states that
absorbance is directly proportional to concentration .
6. What is the Beer-Lambert Law?
A) It states that the absorbance of light is directly proportional to the concentration of
the absorbing substance in a solution
, B) It states that the emission of light is proportional to the concentration of the
substance
C) It states that the refractive index is proportional to concentration
D) It states that the rate of reaction is proportional to concentration
Answer: A
Rationale: The Beer-Lambert Law states that the absorbance of light is directly
proportional to the concentration of the absorbing substance in a solution. This principle is
the foundation of spectrophotometric analysis .
7. What is the principle behind electrophoresis?
A) It separates molecules based on their size and charge using an electric field
B) It measures the absorption of light by molecules
C) It measures the emission of light by excited molecules
D) It separates molecules based on boiling point
Answer: A
Rationale: Electrophoresis separates molecules (e.g., proteins, DNA) based on their size and
charge using an electric field. Charged molecules migrate through a gel or medium at
different rates .
8. What is the difference between end-point and kinetic reactions in clinical
chemistry?
A) End-point reactions measure the final product after the reaction is complete, while
kinetic reactions measure the rate of change during the reaction
B) End-point reactions measure the rate of change, while kinetic reactions measure the
final product
C) Both measure the rate of change
D) Both measure the final product
