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ASCP MLS Exam: Practice Questions

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ASCP MLS Exam: Practice Questions

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400
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$29.99
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About these practice questions

These practice questions will help you prepare for the ASCP MLS exam.

This practice test contains 400 practice questions covering the seven sections of the ASCP MLS exam:

  1. Blood banking
  2. Urinalysis and other body fluids
  3. Chemistry
  4. Hematology
  5. Immunology
  6. Microbiology
  7. Laboratory operations

All questions have been carefully designed to reflect the questions on the real exam, to help you prepare and get a passing grade.

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Sample practice questions

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Section 1: Blood banking

1) Which test screens maternal blood for the presence of fetal red blood cells?
  1. Alpha-fetoprotein screen
  2. Chorionic villus sampling
  3. Direct antiglobulin test
  4. Kleihauer-Betke test
    The Kleihauer-Betke test measures the amount of fetal hemoglobin in the mother's bloodstream. It is used on Rh-negative pregnant women to determine the appropriate dose of Rho(D) immune globulin needed to prevent hemolytic disease of the newborn. If fetal red blood cells enter the mother's bloodstream, her immune system may produce antibodies against the Rh antigen, which can then attack the red blood cells of a future Rh-positive baby.
2) What is the sugar of the A antigen?
  1. D-galactose
    D-galactose is the sugar of the B antigen.
  2. Lactose
  3. N-acetylgalactosamine
    The sugar of the A antigen is N-acetylgalactosamine. This sugar is added to the H antigen to make the A antigen.
  4. N-acetyllactosamine
3) Which test identifies individuals who appear Rh-negative on standard testing but still carry the antigen at low levels?
  1. Kleihauer-Betke Test
  2. Rh phenotyping
  3. Warm autoadsorption test
  4. Weak D test
    Weak D antigens are a variant of the RhD antigen that reacts more weakly than normal RhD antigens in testing. The weak D test identifies people with these weak D antigens.
4) Why is hydroxyethyl starch used in leukocytapheresis procedures?
  1. To help separate white blood cells from red blood cells
    Hydroxyethyl starch (HES) is a common sedimenting agent used in leukocytapheresis procedures. It enhances the separation of white blood cells from red blood cells during centrifugation. This helps decrease the amount of red cell contamination.
  2. To increase the donor’s blood volume
  3. To increase the production of white blood cells in the bone marrow
  4. To pull granulocytes from the marginal pool into the general circulation
5) Which blood product carries the lowest risk of HIV and hepatitis?
  1. Erythrocyte concentrate
  2. Human albumin solution
    Human albumin solution is heated at 60°C for 10 hours to inactivate HIV and hepatitis viruses, thereby virtually eliminating the risk of HIV or hepatitis infection.
  3. Platelets concentrate
  4. Whole blood
6) The absence of which antigen makes red blood cells resistant to Plasmodium vivax malaria?
  1. Duffy
    Red blood cells lacking the Duffy antigen are relatively resistant to infection by Plasmodium vivax, the parasite that causes Plasmodium vivax malaria. The Duffy antigen is absent from the red blood cells of 90% of sub-Saharan Africans, conferring malaria resistance in this population.
  2. Kidd
  3. Lewis
  4. Rhesus
7) Which three HLA molecules are most important to match for kidney transplants?
  1. HLA-A, HLA-B, and HLA-C
  2. HLA-A, HLA-B, and HLA-DR
    Of the six main human leukocyte antigens (HLA-A, HLA-B, HLA-C, HLA-DR, HLA-DQ, and HLA-DP), the three most important for kidney transplantation are HLA-A, HLA-B, and HLA-DR. These antigens play a key role in the immune response to transplanted organs. Mismatches of these antigens increase the risk of transplant rejection.
  3. HLA-A, HLA-DP, and HLA-DQ
  4. HLA-A, HLA-DP, and HLA-DR
8) Which saline is used to help antibodies agglutinate red blood cells?
  1. Buffered blood bank saline
  2. Hypertonic saline
  3. Low ionic strength saline
    Red blood cells have a negative charge. This means that positively charged ions, like sodium ions in saline, gather around the negatively charged red blood cells, creating a net positive charge. The similar charge on all red blood cells causes them to repel each other. This electrical repulsion between red blood cells is called zeta potential. LISS (low ionic strength saline) has fewer sodium ions than normal saline, so this repulsion is reduced, and antibodies can agglutinate red blood cells more easily.
  4. Phosphate-buffered saline
9) When administering immune serum globulin therapy, healthcare professionals should be cautious with patients with:
  1. AIDS
  2. a history of IgA deficiency
    Trace amounts of IgA may be present in immune serum globulin. This can cause life-threatening anaphylaxis in patients who are IgA deficient. This is because IgA is a foreign antigen for IgA-deficient individuals and their immune system may not have developed tolerance to it.
  3. an immunodeficiency disease
  4. idiopathic thrombocytopenic purpura
10) Which acute transfusion complication is most likely to occur if a patient with severe chronic anemia receives a transfusion of whole blood?
  1. Acute intravascular hemolysis
  2. Anaphylactic reaction
  3. Fluid overload
    Patients with chronic anemia have a reduced number of red blood cells. Their bodies compensate by increasing the plasma volume to restore total blood volume. Therefore, these patients do not need the plasma in whole blood transfusions. In fact, whole blood transfusions in these patients may cause transfusion-associated circulatory overload (TACO), which can result in pulmonary edema and heart failure. For this reason, packed red blood cells are preferred for anemic patients.
  4. Septic shock
11) Putting the patient in an upright seated position and providing supplementary oxygen can help for which of these transfusion reactions?
  1. Acute hemolytic transfusion reaction (AHTR)
  2. Transfusion-associated circulatory overload (TACO)
    If a transfusion-associated circulatory overload (TACO) reaction is suspected, then the transfusion must be stopped immediately. The patient should then be placed in a sitting position (also known as Fowler's position) and given supplementary oxygen.
  3. Transfusion-associated sepsis (TAS)
  4. Transfusion-related acute lung injury (TRALI)
12) How much does one unit of red blood cells increase the hemoglobin in a standard adult patient?
  1. 1 g/dL
    For a standard 70 kg adult, one unit of red blood cells typically increases the hemoglobin by 1 gram of hemoglobin per deciliter of blood.
  2. 2 g/dL
  3. 3 g/dL
  4. 4 g/dL
13) Which of these blood products needs to be irradiated before being transfused into patients?
  1. Cryoprecipitate
  2. Fresh frozen plasma
  3. Frozen washed red cells
  4. Granulocytes
    All granulocyte transfusions are routinely irradiated to prevent donor white blood cells from replicating in the patient and causing transfusion-associated graft-versus-host disease.
14) Which pathophysiological effect may result from transfusions of red blood cells with low 2,3-DPG levels?
  1. Decreased carbon dioxide levels
  2. Increased mixed venous oxygen tension
  3. Lower blood viscosity
  4. Tissue hypoxia
    Red blood cells with low 2,3-DPG levels have a higher affinity for oxygen, meaning they bind to oxygen more tightly than normal red blood cells. As a result, less oxygen is released to the tissues, which can lead to tissue hypoxia.
15) Leukocyte-reduced blood products reduce the risk of transmitting:
  1. HIV
  2. cytomegalovirus
    Cytomegalovirus is associated with leukocytes (white blood cells) and can be transmitted through them during transfusion. Leukocytes can be removed from donated blood components through a process called leukoreduction. This process reduces the risk of cytomegalovirus transmission by removing white blood cells that may harbor the virus.
  3. hepatitis C
  4. malaria
16) A 35-year-old woman needs three units of red blood cells. The laboratory performs an antibody screen to identify any blood group antibodies. The antibody screen is positive. According to the results of the antibody panel below, which antibody most likely caused the positive result?
  1. Anti-C
  2. Anti-D
  3. Anti-E
    Cells 3 and 5 caused a reaction (these are the only cells with a +1 in the AHG column). Anti-E is the only antibody that reacts with cells 3 and 5 while showing no reaction with the other cells.
  4. Anti-K
17) Which of these pathogens must donated blood be tested for?
  1. Ebola virus
  2. Hepatitis A virus
    Hepatitis A is not typically tested for during routine blood donation screening because this virus is primarily spread through contaminated food or water, not blood. Furthermore, most people who contract the infection recover completely with no lasting effects.
  3. Streptococcus pneumoniae
  4. West Nile virus
    In the US, all blood donations must be checked for the hepatitis B and C viruses, the human immunodeficiency virus (HIV), the human T-lymphotropic virus, Treponema pallidum (syphilis), and the West Nile virus.
18) Which of these questions is suitable for a blood donor questionnaire?
  1. Have you been on a plane in the past year?
  2. Have you eaten canned food in the past 48 hours?
  3. Have you eaten red meat recently?
  4. Have you had a tattoo in the past 3 months?
    Although uncommon, an unclean tattoo needle can carry bloodborne viruses, such as hepatitis B, hepatitis C, and HIV. For this reason, people with new tattoos are usually advised to wait 3–12 months before giving blood.
19) A certain gene has two alleles: a dominant allele (A) and a recessive allele (a). If 36% of people in a random population have the homozygous recessive genotype (aa), what is the frequency of the recessive allele in this population?
  1. 18%
  2. 24%
  3. 36%
  4. 60%
    To solve this problem we need to use the second Hardy-Weinberg equation, which states p² + 2pq + q² = 1 The relevant parts of the equation are:
    • q = the frequency of the recessive allele (a) in the population
    • q² = the proportion of people with the homozygous recessive genotype (aa)
    The question asks us to find q and tells us that q² = 36%. So to find q, we need to take the square root of q². However, first, we need to convert 36% to a decimal, because the Hardy-Weinberg equations use decimals, not percentages. To convert a percentage to a decimal, divide the percentage by 100: 36% as a decimal = 36/100 = 0.36 Now we can take the square root of q² to find q. Since q² = 0.36, this means q = 0.6 since the square root of 0.36 is 0.6. Finally, multiply by 100 to convert back to a percentage: 0.6 as a percentage = 0.6 × 100 = 60%
20) Which antigen system has the U antigen?
  1. Duffy
  2. Kidd
  3. Lewis
  4. MNS
    U is an antigen from the MNS antigen system. The other important antigens in this system are M, N, S, and s.

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About the ASCP MLS exam

What is the ASCP MLS exam?

The ASCP Medical Laboratory Scientist (MLS) exam assesses the knowledge required for advanced-level medical laboratory roles. The American Society for Clinical Pathology (ASCP) administers the exam.

The exam consists of 100 multiple-choice questions and has a 2.5-hour time limit. Exam topics include blood banking, urinalysis, chemistry, hematology, immunology, microbiology, and laboratory procedures.

The exam fee is $260.

Exam eligibility

Before deciding to take the ASCP MLS exam, first make sure you're eligible.

The exam has five eligibility routes. Each route requires a Bachelor's degree (or equivalent) along with specific certification and/or work experience.

The five routes are:

  1. A Bachelor's degree and completion of a NAACLS-accredited Medical Laboratory Scientist program in the last 5 years
  2. A Bachelor's degree with semesters in Biology and Chemistry, an ASCP MLT (Medical Laboratory Technician) certificate, and 2 years of clinical laboratory experience within the last 5 years.
  3. A Bachelor's degree with semesters in Biology and Chemistry, and 5 years of clinical laboratory experience.
  4. The equivalent of a U.S. Bachelor's degree, an MT/MLS(ASCP) certificate, and 5 years of clinical laboratory experience within the last 10 years.
  5. A Bachelor's degree with semesters in Biology and Chemistry, completion of a 50-week US military medical laboratory training course, and one year of clinical laboratory experience.

To take the ASCP MLS exam, you must meet the criteria for at least one of these five routes.

[ASCP applying and taking]

Content areas

The questions on the ASCP MLS exam encompass seven content areas:

  1. Blood banking
  2. Urinalysis and other body fluids
  3. Chemistry
  4. Hematology
  5. Immunology
  6. Microbiology
  7. Laboratory operations

Focus your study time on just four content areas: Blood banking, Chemistry, Hematology, and Microbiology. These content areas are together worth 80% of the exam. The other three content areas — Urinalysis, Immunology, and Laboratory Operations — are together only worth 20% of the exam, so are not as important.

The following table shows the percentage distribution of the content areas of the exam.

Percentage distribution of the content areas in the ASCP MLS exam.
Content area Percentage of exam
1. Blood banking 17–22%
2. Urinalysis and other body fluids 5–10%
3. Chemistry 17–22%
4. Hematology 17–22%
5. Immunology 5–10%
6. Microbiology 17–22%
7. Laboratory operations 5–10%

The next few pages will provide a detailed overview of each content area.

1. Blood banking

The first content area of the ASCP MLS exam is Blood banking, which is worth 17–22% of the exam. [ASCP MLS/MLT Blood banking]

2. Urinalysis and other body fluids

The second content area of the ASCP MLS exam is Urinalysis and other body fluids, which is worth 5–10% of the exam.

[ASCP MLS/MLT Urinalysis and other body fluids]

3. Chemistry

The third content area of the ASCP MLS exam is Chemistry, which is worth 17–22% of the exam. [ASCP MLS/MLT Chemistry]

4. Hematology

The fourth content area of the ASCP MLS exam is Hematology, which is worth 17–22% of the exam. [ASCP MLS/MLT Hematology]

5. Immunology

The fifth content area of the ASCP MLS exam is Immunology, which is worth 5–10% of the exam. [ASCP MLS/MLT Immunology]

6. Microbiology

The sixth content area of the ASCP MLS exam is Microbiology, which is worth 17–22% of the exam. [ASCP MLS/MLT Microbiology]

7. Laboratory operations

The final content area of the ASCP MLS exam is Laboratory operations, which is worth 5–10% of the exam. [ASCP MLS/MLT Laboratory operations]

This content area may also test you on basic management and education principles.