ASCP BOC QUESTIONS AND ANSWERS | NEW 2026
UPDATE | WITH COMPLETE SOLUTION!!
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
UPDATE | WITH COMPLETE SOLUTION!!
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
