ASCP: BOC -Exam Questions with
Guaranteed Pass Solutions 2026-2027
Updated.
Which enzyme catalyzes the conversion of starch to glucose and maltose? - Answer Amylase
Nephelometers measure light: - Answer Scattered at a right angle to the light path
A serum sample demonstrates an elevated result when tested with the Jaffe reaction. This
indicates: - Answer Renal functional impairment
A vaginal/rectal swab is collected from a pregnant patient to screen for group B Streptococcus
colonization. What is the best medium to use for specimen inoculation? - Answer Lim Broth
When testing a patient for HIV antibody, what is used to confirm a positive screening test? -
Answer Western Blot
An isolate from a stool culture gives the following growth characteristics and biochemical
reactions:
MAC: Colorless colonies
HE agar: Yellow-Orange colonies
TSI: Acid slant/acid butt, no gas, no h2s
Urea: Positive
These screening results are consistent with which enteric pathogen? - Answer Yersinia
entercolitica. Yersinia produces yellow colonies on HE because it can ferment sucrose.
When stool examination is negative, the preferred specimen for the diagnosis of paragonimiasis
is: - Answer Sputum. Paragonimus worms live in cystic cavities in the lungs. Ova may be
found in sputum, or swallowed and passed in stool.
A branching gram-positive, partially acid-fast organism is isolated from a bronchial washing on a
63-year-old woman receiving chemotherapy. The organism does not hydrolyze casein, tyrosine
or xanthine. The most likely identification is: - Answer Nocardia asteroides. (THINK BECAUSE
OF THE BRANCHING). It is partially acid fast and does not hydrolyze the substrates casein,
tyrosine, or xanthine.
,Use of only male donors as a source of plasma intended for transfusion is advocated to reduce
which type of reaction? - Answer TRALI. TRALI is most commonly caused by donor HLA or
granulocyte-specific antibodies that react with recipient antigens, causing damage to the lung
basement membrane and bilateral pulmonary edema within 6 hours of transfusion. Multiparous
females are more likely to have antibodies than males. Using male donors as the sole source of
plasma products is a strategy for reducing the risk of TRALI.
The result of an anti-nuclear antibody test was a titer of 1:320 with a peripheral pattern. What
best correlates with these results? - Answer Anti-dsDNA Titer 1:80. and a high titer of
antibodies to Sm. Peripheral pattern reacts with the antigenic determinants of double
strandedness of DNA.
Abnormalities found in erythroleukemia include: - Answer Megaloblastoid development.
Which factor will not interfere with the reagent strip test for leukocytes in urine? - Answer
Nitrite. Nitrite is produced by bacteria, and WBCs are found when there is a bacterial infection.
If nitrite interfered with the WBC reaction, then the dipstick would be worthless when testing
patients with UTIs.
Which locus is used to identify the gender of the individual from whom a DNA sample is
obtained? - Answer Amelogenin. Amelogenin gives different sized amplicons based on
whether it is amplified from the X or Y chromosomes, so males would have 2 bands on a gel at
the amelogenin locus, while females would have only 1.
Penicillium species is isolated from a bone marrow culture of a patient that travelled to
southeast Asia. After 7 days the isolate produces a red pigment that diffuses into the medium.
The technologist should: - Answer Transfer a colony to BHI at 35 degrees. C. Penicillium
marneffiei is a dimorphic fungi that produces a diffusible red pigment.
An elevated serum iron with normal iron binding capacity is most likely associated with: -
Answer Pernicious anemia. Ineffective erythropoiesis. High iron turnover.
Which enzyme substrate is the most specific for prostatic acid phosphatase for quantitative
endpoint reactions? - Answer Thymolphthalein monophosphate. Thymolphthalein
monophosphate is the most specific substrate of choice for quantitative endpoint reactions;
however, p-nitrophenylphosphate is the preferred substrate for continuous monitoring.
The principle of the tablet test for bilirubin in urine or feces is: - Answer Chemical coupling of
bilirubin with a diazonium salt to form a purple color.
Ghost red blood cells are seen in urine that is: - Answer Alkaline and dilute. RBCs absorb
water when in dilute urine, and are also less preserved in alkaline urine. Therefore, as the cells
,swell in the alkaline urine, the cell membrane allows hemoglobin to leak from the cell, resulting
in the empty cell membrane and the pale appearance.
In the cold agglutinin test, the tubes containing the serum and erythrocytes are allowed to
stand overnight in the refrigerator, and the results are read the next morning. If a disk of the
erythrocytes floats up from the bottom of the tube with only the flick of finger, this is read as a:
- Answer A 4+ reaction. When one solid agglutinate is present, the reaction is classified as 4+.
A bone marrow shows foam cells ranging from 20-100 μm in size, vacuolated cytoplasm
containing sphingomyelin and is faintly PAS+. This cell type is most characteristic of: - Answer
Niemann-Pick Disease
The presence of leukocytes in urine is known as: - Answer Pyuria
In what metabolic disease will urine turn dark brown to black upon standing? - Answer
Alkaptonuria
First-generation cephalosporins can be adequately represented by: - Answer Cephalothin
According to AABB Standards, Platelets prepared from Whole Blood shall have at least: - Answer
5.5x10^10 platelets per unit in at least 90% of the units tested
A stool specimen that appears black and tarry should be tested for the presence of: - Answer
Occult blood
Sodium bicarbonate and sodium citrate are components of which of the following? - Answer
JEMBEC system. The JEMBEC system is a transport and inoculation medium used for direct
plating of specimens for N gonorrhoeae. Chocolate based selective medium is inoculated with
the specimen. This is placed in an impermeable plastic bag with a bicarbonatesodium citrate
pellet that absorbs moisture to generate a carbon dioxide-rich environment.
A 44-year-old man was admitted to the hospital following a 2-week history of low-grade fever,
malaise and anorexia. Examination of a Giemsa stain revealed many intraerythrocytic parasites.
Further history revealed frequent camping trips near Martha's Vineyard and Nantucket Island,
but no travel outside the continental United States. This parasite could easily be confused with:
- Answer Plasmodium falciparum. The patient's history is suggestive of Babesia infection.
Babesia microti ring forms are similar to Plasmodium falciparum. A travel history is helpful in
determining the cause of infection.
Platelets prepared in a polyolefin type container, stored at 22° - 24°C in 50 mL of plasma, and
gently agitated can be used for up to: - Answer 5 days.
, A 29-year-old man is seen for recurrence of a purulent urethral discharge 10 days after the
successful treatment of culture proven gonorrhea. The most likely etiology of his urethritis is: -
Answer Chlamydia trachomatis. Up to 1/3 of patients with Neisseria gonorrhoeae infection
are also coinfected with Chlamydia trachomatis. Patients with identified infection with one
organism are usually treated for both infections.
The (8;14) chromosomal translocation brings which of the following 2 genes in close proximity?
- Answer C-myc and the immunoglobulin heavy chain. The t(8;14) typically found in Burkitt
leukemia (ALL-L3), brings the master cell cycle control factor c-myc on chromosome 8 under the
influence of the strong immunoglobulin heavy chain promoter on chromosome 14, driving a
leukemogenic process.
The technologist observes apparent homogenous staining of the nucleus of interphase cells
while performing an IFA-ANA, as well as staining of the chromosomes in mitotic cells. This result
is: - Answer Expected for anti-DNA antibodies.
An AFB broth culture is positive for acid-fast bacilli at 1 week while the agar slant shows no
growth. The most likely explanation for this is: - Answer AFB grow more rapidly in liquid
media.
A strict anaerobe that produces terminal spores is: - Answer Clostridium tetani.
When genotyping strains of bacteria by PFGE, what is the minimum number of genetic
differences that must be observed between a reference strain and a test strain before it can be
determined that the test strain is unrelated to the reference strain? - Answer 3.
In skin tests, a wheal and flare development is indicative of: - Answer Immediate
hypersensitivity. Immediate hypersensitivity is tested by skin tests with edema and erythema,
which also can be called wheal and flare.
The visible serological reaction between soluble antigen and its specific antibody is: - Answer
Precipitation
An urinalysis performed on a 2-week-old infant with diarrhea shows a negative reaction with
the glucose oxidase reagent strip. A copper reduction tablet test should be performed to check
the urine sample for the presence of: - Answer Galactose. Children with failure to thrive may
have galactosuria. Since the reagent strip for glucose is negative, this leaves galactose.
In an uncomplicated case of severe iron deficiency anemia, what represents the typical pattern
of results? - Answer Iron deficiency anemia laboratory features include: decreased RBC,
Guaranteed Pass Solutions 2026-2027
Updated.
Which enzyme catalyzes the conversion of starch to glucose and maltose? - Answer Amylase
Nephelometers measure light: - Answer Scattered at a right angle to the light path
A serum sample demonstrates an elevated result when tested with the Jaffe reaction. This
indicates: - Answer Renal functional impairment
A vaginal/rectal swab is collected from a pregnant patient to screen for group B Streptococcus
colonization. What is the best medium to use for specimen inoculation? - Answer Lim Broth
When testing a patient for HIV antibody, what is used to confirm a positive screening test? -
Answer Western Blot
An isolate from a stool culture gives the following growth characteristics and biochemical
reactions:
MAC: Colorless colonies
HE agar: Yellow-Orange colonies
TSI: Acid slant/acid butt, no gas, no h2s
Urea: Positive
These screening results are consistent with which enteric pathogen? - Answer Yersinia
entercolitica. Yersinia produces yellow colonies on HE because it can ferment sucrose.
When stool examination is negative, the preferred specimen for the diagnosis of paragonimiasis
is: - Answer Sputum. Paragonimus worms live in cystic cavities in the lungs. Ova may be
found in sputum, or swallowed and passed in stool.
A branching gram-positive, partially acid-fast organism is isolated from a bronchial washing on a
63-year-old woman receiving chemotherapy. The organism does not hydrolyze casein, tyrosine
or xanthine. The most likely identification is: - Answer Nocardia asteroides. (THINK BECAUSE
OF THE BRANCHING). It is partially acid fast and does not hydrolyze the substrates casein,
tyrosine, or xanthine.
,Use of only male donors as a source of plasma intended for transfusion is advocated to reduce
which type of reaction? - Answer TRALI. TRALI is most commonly caused by donor HLA or
granulocyte-specific antibodies that react with recipient antigens, causing damage to the lung
basement membrane and bilateral pulmonary edema within 6 hours of transfusion. Multiparous
females are more likely to have antibodies than males. Using male donors as the sole source of
plasma products is a strategy for reducing the risk of TRALI.
The result of an anti-nuclear antibody test was a titer of 1:320 with a peripheral pattern. What
best correlates with these results? - Answer Anti-dsDNA Titer 1:80. and a high titer of
antibodies to Sm. Peripheral pattern reacts with the antigenic determinants of double
strandedness of DNA.
Abnormalities found in erythroleukemia include: - Answer Megaloblastoid development.
Which factor will not interfere with the reagent strip test for leukocytes in urine? - Answer
Nitrite. Nitrite is produced by bacteria, and WBCs are found when there is a bacterial infection.
If nitrite interfered with the WBC reaction, then the dipstick would be worthless when testing
patients with UTIs.
Which locus is used to identify the gender of the individual from whom a DNA sample is
obtained? - Answer Amelogenin. Amelogenin gives different sized amplicons based on
whether it is amplified from the X or Y chromosomes, so males would have 2 bands on a gel at
the amelogenin locus, while females would have only 1.
Penicillium species is isolated from a bone marrow culture of a patient that travelled to
southeast Asia. After 7 days the isolate produces a red pigment that diffuses into the medium.
The technologist should: - Answer Transfer a colony to BHI at 35 degrees. C. Penicillium
marneffiei is a dimorphic fungi that produces a diffusible red pigment.
An elevated serum iron with normal iron binding capacity is most likely associated with: -
Answer Pernicious anemia. Ineffective erythropoiesis. High iron turnover.
Which enzyme substrate is the most specific for prostatic acid phosphatase for quantitative
endpoint reactions? - Answer Thymolphthalein monophosphate. Thymolphthalein
monophosphate is the most specific substrate of choice for quantitative endpoint reactions;
however, p-nitrophenylphosphate is the preferred substrate for continuous monitoring.
The principle of the tablet test for bilirubin in urine or feces is: - Answer Chemical coupling of
bilirubin with a diazonium salt to form a purple color.
Ghost red blood cells are seen in urine that is: - Answer Alkaline and dilute. RBCs absorb
water when in dilute urine, and are also less preserved in alkaline urine. Therefore, as the cells
,swell in the alkaline urine, the cell membrane allows hemoglobin to leak from the cell, resulting
in the empty cell membrane and the pale appearance.
In the cold agglutinin test, the tubes containing the serum and erythrocytes are allowed to
stand overnight in the refrigerator, and the results are read the next morning. If a disk of the
erythrocytes floats up from the bottom of the tube with only the flick of finger, this is read as a:
- Answer A 4+ reaction. When one solid agglutinate is present, the reaction is classified as 4+.
A bone marrow shows foam cells ranging from 20-100 μm in size, vacuolated cytoplasm
containing sphingomyelin and is faintly PAS+. This cell type is most characteristic of: - Answer
Niemann-Pick Disease
The presence of leukocytes in urine is known as: - Answer Pyuria
In what metabolic disease will urine turn dark brown to black upon standing? - Answer
Alkaptonuria
First-generation cephalosporins can be adequately represented by: - Answer Cephalothin
According to AABB Standards, Platelets prepared from Whole Blood shall have at least: - Answer
5.5x10^10 platelets per unit in at least 90% of the units tested
A stool specimen that appears black and tarry should be tested for the presence of: - Answer
Occult blood
Sodium bicarbonate and sodium citrate are components of which of the following? - Answer
JEMBEC system. The JEMBEC system is a transport and inoculation medium used for direct
plating of specimens for N gonorrhoeae. Chocolate based selective medium is inoculated with
the specimen. This is placed in an impermeable plastic bag with a bicarbonatesodium citrate
pellet that absorbs moisture to generate a carbon dioxide-rich environment.
A 44-year-old man was admitted to the hospital following a 2-week history of low-grade fever,
malaise and anorexia. Examination of a Giemsa stain revealed many intraerythrocytic parasites.
Further history revealed frequent camping trips near Martha's Vineyard and Nantucket Island,
but no travel outside the continental United States. This parasite could easily be confused with:
- Answer Plasmodium falciparum. The patient's history is suggestive of Babesia infection.
Babesia microti ring forms are similar to Plasmodium falciparum. A travel history is helpful in
determining the cause of infection.
Platelets prepared in a polyolefin type container, stored at 22° - 24°C in 50 mL of plasma, and
gently agitated can be used for up to: - Answer 5 days.
, A 29-year-old man is seen for recurrence of a purulent urethral discharge 10 days after the
successful treatment of culture proven gonorrhea. The most likely etiology of his urethritis is: -
Answer Chlamydia trachomatis. Up to 1/3 of patients with Neisseria gonorrhoeae infection
are also coinfected with Chlamydia trachomatis. Patients with identified infection with one
organism are usually treated for both infections.
The (8;14) chromosomal translocation brings which of the following 2 genes in close proximity?
- Answer C-myc and the immunoglobulin heavy chain. The t(8;14) typically found in Burkitt
leukemia (ALL-L3), brings the master cell cycle control factor c-myc on chromosome 8 under the
influence of the strong immunoglobulin heavy chain promoter on chromosome 14, driving a
leukemogenic process.
The technologist observes apparent homogenous staining of the nucleus of interphase cells
while performing an IFA-ANA, as well as staining of the chromosomes in mitotic cells. This result
is: - Answer Expected for anti-DNA antibodies.
An AFB broth culture is positive for acid-fast bacilli at 1 week while the agar slant shows no
growth. The most likely explanation for this is: - Answer AFB grow more rapidly in liquid
media.
A strict anaerobe that produces terminal spores is: - Answer Clostridium tetani.
When genotyping strains of bacteria by PFGE, what is the minimum number of genetic
differences that must be observed between a reference strain and a test strain before it can be
determined that the test strain is unrelated to the reference strain? - Answer 3.
In skin tests, a wheal and flare development is indicative of: - Answer Immediate
hypersensitivity. Immediate hypersensitivity is tested by skin tests with edema and erythema,
which also can be called wheal and flare.
The visible serological reaction between soluble antigen and its specific antibody is: - Answer
Precipitation
An urinalysis performed on a 2-week-old infant with diarrhea shows a negative reaction with
the glucose oxidase reagent strip. A copper reduction tablet test should be performed to check
the urine sample for the presence of: - Answer Galactose. Children with failure to thrive may
have galactosuria. Since the reagent strip for glucose is negative, this leaves galactose.
In an uncomplicated case of severe iron deficiency anemia, what represents the typical pattern
of results? - Answer Iron deficiency anemia laboratory features include: decreased RBC,
