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ASCP MLS EXAM PRACTICE EXAM LATEST
UPDATE 2026-2027 QUESTIONS AND
DETAILED SOLUTIONS WITH RATIONALES
Question: A 1:100 dilution of a patient's peripheral blood was made, and a total of 136 platelets
were counted in 5 squares of the RBC area of a Neubauer-ruled hemocytometer. What is the
platelet count? Note: Volume correction factor is 50 uL. - CORRECT ANSWER✔✔680 x 10^3 (DF
x total platelets x volume correction factor)
Question: Which Lewis blood group system phenotype produces anti-Le(a)? - CORRECT
ANSWER✔✔Le(a-b-)
Question: While many isolates of this organism remain susceptible to penicillin, resistance is
increasing in some areas due to the organism's altered penicillin binding proteins. In such cases,
the recommended treatment is erythromycin or chloramphenicol. Which of the following
organisms does this describe?
A. Enterococcus faecium
, Page 2 of 34
B. Staphylococcus aureus
C. Klebsiella pneumoniae
D. Streptococcus pneumoniae - CORRECT ANSWER✔✔Streptococcus pneumoniae
Question: The number of patients correctly diagnosed for the disease or not having the disease
are defined as: - CORRECT ANSWER✔✔Efficiency
Question: The oocyst for this organism typically contains two sporocysts. However, in patient
specimens of the sporocysts (containing four sporozoites) that are released from the oocyst are
seen singly. Which of the following organisms does this represent?
A. Cystiosporia belli
B. Sarcocystis species
C. Cryptosporidium parvum
D. Blastocystis hominis - CORRECT ANSWER✔✔Sarcocystis species
, Page 3 of 34
Question: Nitrous oxide is associated with the prevention of vaso-occlusion by decreasing
cellular adherence to endothelium. Which amino acid is decreased in patients with sickle cell
disease and is needed as a substrate to produce nitric oxide? - CORRECT ANSWER✔✔L-arginine
Question: A patient has a repeated history of spontaneous abortion. Coagulation studies reveal
an elevated APTT, normal PT, normal platelet function, and normal thrombin time. Schistocytes
were seen on the peripheral blood smear. Which test should be used to determine if a patient
has lupus anticoagulant?
A. Factor VIII assay
B. Mixing studies with factor-deficient plasmas
C. ANA test
D. Platelet neutralization test - CORRECT ANSWER✔✔Platelet neutralization test
Question: On SBA, Haemophilus influenzae will exhibit satellitism around around all of the
following bacteria except:
A. Pseudomonas spp.
B. Neisseria spp.
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C. Staphylococcus spp.
D. Streptococcus pneumoniae - CORRECT ANSWER✔✔Pseudomonas spp.
Q:A patient has a high absolute eosinophil count of 2000/uL. Organ biopsies show infiltration of
eosinophils. The patient is diagnosed as having Chronic Eosinophilic Leukemia. Other causes for
high eosinophil counts include all of the following except:
A. Infections of parasitic helminths
B. Allergic reactions
C. Chronic myelogenous leukemia
D. Mycosis fungoides - CORRECT ANSWER✔✔Mycosis fungoides
Question: Vaccines can be divided into these experimental types: - CORRECT ANSWER✔✔Live,
attenuated; inactivated; toxoid
Question: A patient is seen in the ER for abdominal pain and jaundice. A urinalysis noted there
is an increase in urobilinogen. All of the following are likely causes except:
A. Hepatitis
ASCP MLS EXAM PRACTICE EXAM LATEST
UPDATE 2026-2027 QUESTIONS AND
DETAILED SOLUTIONS WITH RATIONALES
Question: A 1:100 dilution of a patient's peripheral blood was made, and a total of 136 platelets
were counted in 5 squares of the RBC area of a Neubauer-ruled hemocytometer. What is the
platelet count? Note: Volume correction factor is 50 uL. - CORRECT ANSWER✔✔680 x 10^3 (DF
x total platelets x volume correction factor)
Question: Which Lewis blood group system phenotype produces anti-Le(a)? - CORRECT
ANSWER✔✔Le(a-b-)
Question: While many isolates of this organism remain susceptible to penicillin, resistance is
increasing in some areas due to the organism's altered penicillin binding proteins. In such cases,
the recommended treatment is erythromycin or chloramphenicol. Which of the following
organisms does this describe?
A. Enterococcus faecium
, Page 2 of 34
B. Staphylococcus aureus
C. Klebsiella pneumoniae
D. Streptococcus pneumoniae - CORRECT ANSWER✔✔Streptococcus pneumoniae
Question: The number of patients correctly diagnosed for the disease or not having the disease
are defined as: - CORRECT ANSWER✔✔Efficiency
Question: The oocyst for this organism typically contains two sporocysts. However, in patient
specimens of the sporocysts (containing four sporozoites) that are released from the oocyst are
seen singly. Which of the following organisms does this represent?
A. Cystiosporia belli
B. Sarcocystis species
C. Cryptosporidium parvum
D. Blastocystis hominis - CORRECT ANSWER✔✔Sarcocystis species
, Page 3 of 34
Question: Nitrous oxide is associated with the prevention of vaso-occlusion by decreasing
cellular adherence to endothelium. Which amino acid is decreased in patients with sickle cell
disease and is needed as a substrate to produce nitric oxide? - CORRECT ANSWER✔✔L-arginine
Question: A patient has a repeated history of spontaneous abortion. Coagulation studies reveal
an elevated APTT, normal PT, normal platelet function, and normal thrombin time. Schistocytes
were seen on the peripheral blood smear. Which test should be used to determine if a patient
has lupus anticoagulant?
A. Factor VIII assay
B. Mixing studies with factor-deficient plasmas
C. ANA test
D. Platelet neutralization test - CORRECT ANSWER✔✔Platelet neutralization test
Question: On SBA, Haemophilus influenzae will exhibit satellitism around around all of the
following bacteria except:
A. Pseudomonas spp.
B. Neisseria spp.
, Page 4 of 34
C. Staphylococcus spp.
D. Streptococcus pneumoniae - CORRECT ANSWER✔✔Pseudomonas spp.
Q:A patient has a high absolute eosinophil count of 2000/uL. Organ biopsies show infiltration of
eosinophils. The patient is diagnosed as having Chronic Eosinophilic Leukemia. Other causes for
high eosinophil counts include all of the following except:
A. Infections of parasitic helminths
B. Allergic reactions
C. Chronic myelogenous leukemia
D. Mycosis fungoides - CORRECT ANSWER✔✔Mycosis fungoides
Question: Vaccines can be divided into these experimental types: - CORRECT ANSWER✔✔Live,
attenuated; inactivated; toxoid
Question: A patient is seen in the ER for abdominal pain and jaundice. A urinalysis noted there
is an increase in urobilinogen. All of the following are likely causes except:
A. Hepatitis
