ASCP BOC EXAM 2026 WITH 100%
CORRECT ANSWERS
Which enzyme catalyzes the conversion of starch to glucose and maltose? - Precise Answer
✔✔Amylase
Nephelometers measure light: - Precise 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: - Precise 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? - Precise Answer
✔✔Lim Broth
When testing a patient for HIV antibody, what is used to confirm a positive screening test? -
Precise 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? - Precise 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: - Precise 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: - Precise 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? - Precise 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? - Precise 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: - Precise Answer ✔✔Megaloblastoid
development.
Which factor will not interfere with the reagent strip test for leukocytes in urine? - Precise
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? - Precise 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: - Precise 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: -
Precise Answer ✔✔Pernicious anemia. Ineffective erythropoiesis. High iron turnover.
Which enzyme substrate is the most specific for prostatic acid phosphatase for quantitative
endpoint reactions? - Precise 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: - Precise Answer ✔✔Chemical
coupling of bilirubin with a diazonium salt to form a purple color.
Ghost red blood cells are seen in urine that is: - Precise 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:
,- Precise 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: - Precise
Answer ✔✔Niemann-Pick Disease
The presence of leukocytes in urine is known as: - Precise Answer ✔✔Pyuria
In what metabolic disease will urine turn dark brown to black upon standing? - Precise Answer
✔✔Alkaptonuria
First-generation cephalosporins can be adequately represented by: - Precise Answer
✔✔Cephalothin
According to AABB Standards, Platelets prepared from Whole Blood shall have at least: - Precise
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: - Precise
Answer ✔✔Occult blood
Sodium bicarbonate and sodium citrate are components of which of the following? - Precise
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:
- Precise 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: - Precise 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: -
Precise 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?
- Precise 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: - Precise 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: - Precise Answer ✔✔AFB grow more rapidly in
liquid media.
A strict anaerobe that produces terminal spores is: - Precise 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? - Precise Answer ✔✔3.
In skin tests, a wheal and flare development is indicative of: - Precise 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: - Precise
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: - Precise 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? - Precise Answer ✔✔Iron deficiency anemia laboratory features include: decreased
RBC, hemoglobin, MCV, MCH, MCHC, serum iron, serum ferritin % saturation, bone marrow iron
stores; and increased RDW, TIBC, FEP and serum soluble transferrin receptor levels.
Incompatibility by which of the following procedures is an absolute contraindication to
allotransplantation? - Precise Answer ✔✔ABO grouping. ABO incompatibility results in
hyperacute rejection. This reaction is mediated by anti-A or anti-B antibodies that naturally
occur in individuals who lack the corresponding A or B antigen.
In a delayed hemolytic transfusion reaction, the direct antiglobulin test is typically: - Precise
Answer ✔✔Mixed-field positive. Delayed hemolytic transfusion reactions are associated with
extravascular hemolysis, rather than intravascular. Alloantibody coats the transfused antigen-
positive donor cells in the recipient's circulation, producing a mixed-field positive reaction in the
DAT.
Urine samples should be examined within 1 hour of voiding because: - Precise Answer
CORRECT ANSWERS
Which enzyme catalyzes the conversion of starch to glucose and maltose? - Precise Answer
✔✔Amylase
Nephelometers measure light: - Precise 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: - Precise 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? - Precise Answer
✔✔Lim Broth
When testing a patient for HIV antibody, what is used to confirm a positive screening test? -
Precise 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? - Precise 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: - Precise 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: - Precise 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? - Precise 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? - Precise 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: - Precise Answer ✔✔Megaloblastoid
development.
Which factor will not interfere with the reagent strip test for leukocytes in urine? - Precise
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? - Precise 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: - Precise 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: -
Precise Answer ✔✔Pernicious anemia. Ineffective erythropoiesis. High iron turnover.
Which enzyme substrate is the most specific for prostatic acid phosphatase for quantitative
endpoint reactions? - Precise 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: - Precise Answer ✔✔Chemical
coupling of bilirubin with a diazonium salt to form a purple color.
Ghost red blood cells are seen in urine that is: - Precise 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:
,- Precise 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: - Precise
Answer ✔✔Niemann-Pick Disease
The presence of leukocytes in urine is known as: - Precise Answer ✔✔Pyuria
In what metabolic disease will urine turn dark brown to black upon standing? - Precise Answer
✔✔Alkaptonuria
First-generation cephalosporins can be adequately represented by: - Precise Answer
✔✔Cephalothin
According to AABB Standards, Platelets prepared from Whole Blood shall have at least: - Precise
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: - Precise
Answer ✔✔Occult blood
Sodium bicarbonate and sodium citrate are components of which of the following? - Precise
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:
- Precise 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: - Precise 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: -
Precise 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?
- Precise 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: - Precise 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: - Precise Answer ✔✔AFB grow more rapidly in
liquid media.
A strict anaerobe that produces terminal spores is: - Precise 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? - Precise Answer ✔✔3.
In skin tests, a wheal and flare development is indicative of: - Precise 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: - Precise
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: - Precise 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? - Precise Answer ✔✔Iron deficiency anemia laboratory features include: decreased
RBC, hemoglobin, MCV, MCH, MCHC, serum iron, serum ferritin % saturation, bone marrow iron
stores; and increased RDW, TIBC, FEP and serum soluble transferrin receptor levels.
Incompatibility by which of the following procedures is an absolute contraindication to
allotransplantation? - Precise Answer ✔✔ABO grouping. ABO incompatibility results in
hyperacute rejection. This reaction is mediated by anti-A or anti-B antibodies that naturally
occur in individuals who lack the corresponding A or B antigen.
In a delayed hemolytic transfusion reaction, the direct antiglobulin test is typically: - Precise
Answer ✔✔Mixed-field positive. Delayed hemolytic transfusion reactions are associated with
extravascular hemolysis, rather than intravascular. Alloantibody coats the transfused antigen-
positive donor cells in the recipient's circulation, producing a mixed-field positive reaction in the
DAT.
Urine samples should be examined within 1 hour of voiding because: - Precise Answer
