MLS ASCP EXAM 2025 QUESTIONS AND
ANSWERS
C antigen is most common in blacks and whites; anti-c would be most common reactive -
ANS Rh antibodies show enhanced reactivity with enzyme pretreated cells. The M and Fya
antigens are cleaved from enzyme pretreated cells and therefore there would be no reaction
between enzyme pretreated cells and serum containing anti-M or anti-Fya. The incidence of the
c antigen is 80% in whites and 96% in blacks. The incidence of the E antigen is 29% in whites
and 22% in blacks. Increased reactivity with enzyme pretreated cells and incompatible results
with 8 of 10 donor units is most likely due to anti-c.
Procainamide - ANS NAPA
loose clusters of small spherical microconidia, positive urease - ANS Trichophyton
mentagrophytes
BHCG tumor marker - ANS chorocarcinoma
5HIAA - ANS carcinoid tumors
Proteus vulgaris vs P. mirabilis indole test - ANS P. vulgaris is indole pos. P. mirabilis is indole
neg
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, Hydatid cyst fluid - ANS used to neutralize Anti-P1 antibody
Antacid overdose - ANS Check pH
Prolonged PT, PTT, and thrombin after collecting from catheter - ANS heparin contamination
mixing study that was performed with a prolonged PTT that couldn't be corrected -
ANS DRVVT (Dilute Russell Viper Venom Test)
two pt's ran in duplicate (PT and PTT). The PTT seemed to always be prolonged but PT looked
ok - ANS check the CaCl/phospholipid reagent delivery
Patient is on coumadin therapy, what will be affected - ANS Decreased protein C
Lot's of stomatocytes - ANS Liver disease
Burr cells - ANS Uremia
Picture of target cells with hemoglobin C crystals. The white count was high on instrument 1, so
a second instrument was used with a stronger lysing agent, and the white count was corrected -
ANS anti-lysing target cells are what increased the white count? Erythrocytes containing
hemoglobin C do not lyse normally (sickle cell diseases)
A sodium citrate tube was drawn for a HCT on a pt but the hematocrit was abnormal -
ANS recollect with decreased anticoagulant. high hct (>55%) causes low plasma so you need
less anticoagulant
Question that gives a red blood cells count, HGB, and HCT. I did the rule of 3 and found that the
2
HGB didn't meet the rule of 3 because it was too high - ANS check for lipemia (elevates HGB)
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, PBS with an elevated reticulocyte count and howell jolly bodies in the RBC's - ANS Prussian
blue for howell jolly bodies made of iron. Prussian blue stain, which is not taken up by
reticulocytes, is helpful in differentiating the two.
what is composed of DNA? - ANS howell jolly bodies
what falsely increases ESR - ANS vibration, tilting of tube, higher temps, >1 hr test time,
improper mixing of blood, improper dilution
factors decreasing ESR - ANS Polycythemia, Microcytosis (Hb C), Sickle cells, spherocytes,
Anti-inflammatory medications, Hypogammaglobulinemia, Hypofibrinogenemia (DIC), High
WBC count, Hyperviscosity
Factors increasing ESR - ANS Anemia, Macrocytosis, Female gender, Age >50 years, Obesity,
Pregnancy, Hypercholesterolemia, cancer, multiple myeloma, rouleaux, infections,
inflammation
what falsely decreases ESR - ANS low blood/ room temps, air bubbles, tests <1 hr, improper
mixing of blood, improper dilution
lactic acid collection - ANS separate from serum and put on ice
coefficient of variation - ANS (standard deviation/ mean) X 100
Carbon dioxide electrode measures what - ANS Used to measure free carbon dioxide ions by
detecting pH. The change in pH is measured by an internal pH sensor, which is proportional to
the carbon dioxide level.
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ANSWERS
C antigen is most common in blacks and whites; anti-c would be most common reactive -
ANS Rh antibodies show enhanced reactivity with enzyme pretreated cells. The M and Fya
antigens are cleaved from enzyme pretreated cells and therefore there would be no reaction
between enzyme pretreated cells and serum containing anti-M or anti-Fya. The incidence of the
c antigen is 80% in whites and 96% in blacks. The incidence of the E antigen is 29% in whites
and 22% in blacks. Increased reactivity with enzyme pretreated cells and incompatible results
with 8 of 10 donor units is most likely due to anti-c.
Procainamide - ANS NAPA
loose clusters of small spherical microconidia, positive urease - ANS Trichophyton
mentagrophytes
BHCG tumor marker - ANS chorocarcinoma
5HIAA - ANS carcinoid tumors
Proteus vulgaris vs P. mirabilis indole test - ANS P. vulgaris is indole pos. P. mirabilis is indole
neg
1
Page
@COPYRIGHT @THEBRIGHT 2025/2026
, Hydatid cyst fluid - ANS used to neutralize Anti-P1 antibody
Antacid overdose - ANS Check pH
Prolonged PT, PTT, and thrombin after collecting from catheter - ANS heparin contamination
mixing study that was performed with a prolonged PTT that couldn't be corrected -
ANS DRVVT (Dilute Russell Viper Venom Test)
two pt's ran in duplicate (PT and PTT). The PTT seemed to always be prolonged but PT looked
ok - ANS check the CaCl/phospholipid reagent delivery
Patient is on coumadin therapy, what will be affected - ANS Decreased protein C
Lot's of stomatocytes - ANS Liver disease
Burr cells - ANS Uremia
Picture of target cells with hemoglobin C crystals. The white count was high on instrument 1, so
a second instrument was used with a stronger lysing agent, and the white count was corrected -
ANS anti-lysing target cells are what increased the white count? Erythrocytes containing
hemoglobin C do not lyse normally (sickle cell diseases)
A sodium citrate tube was drawn for a HCT on a pt but the hematocrit was abnormal -
ANS recollect with decreased anticoagulant. high hct (>55%) causes low plasma so you need
less anticoagulant
Question that gives a red blood cells count, HGB, and HCT. I did the rule of 3 and found that the
2
HGB didn't meet the rule of 3 because it was too high - ANS check for lipemia (elevates HGB)
Page
@COPYRIGHT @THEBRIGHT 2025/2026
, PBS with an elevated reticulocyte count and howell jolly bodies in the RBC's - ANS Prussian
blue for howell jolly bodies made of iron. Prussian blue stain, which is not taken up by
reticulocytes, is helpful in differentiating the two.
what is composed of DNA? - ANS howell jolly bodies
what falsely increases ESR - ANS vibration, tilting of tube, higher temps, >1 hr test time,
improper mixing of blood, improper dilution
factors decreasing ESR - ANS Polycythemia, Microcytosis (Hb C), Sickle cells, spherocytes,
Anti-inflammatory medications, Hypogammaglobulinemia, Hypofibrinogenemia (DIC), High
WBC count, Hyperviscosity
Factors increasing ESR - ANS Anemia, Macrocytosis, Female gender, Age >50 years, Obesity,
Pregnancy, Hypercholesterolemia, cancer, multiple myeloma, rouleaux, infections,
inflammation
what falsely decreases ESR - ANS low blood/ room temps, air bubbles, tests <1 hr, improper
mixing of blood, improper dilution
lactic acid collection - ANS separate from serum and put on ice
coefficient of variation - ANS (standard deviation/ mean) X 100
Carbon dioxide electrode measures what - ANS Used to measure free carbon dioxide ions by
detecting pH. The change in pH is measured by an internal pH sensor, which is proportional to
the carbon dioxide level.
3
Page
@COPYRIGHT @THEBRIGHT 2025/2026
