MLT ASCP Chemistry Practice
Questions With Correct Answers
Latest Update 2025/2026 GRADED A+
Which one of the following statements about acetaminophen metabolism is false?
Choose the single best answer
A. It is metabolized in the kidney
B. It is largely metabolized in the liver to glucuronide and sulfonate conjugates
C. A small amount is metabolized via cytochrome oxidase to a reactive
benzoquinoneimine intermediate
D. This intermediate becomes toxic to the liver once tissue glutathione becomes
depleted - correct answerA;
The benzoquinoneimine intermediate produced in the liver as a result of hepatic
cytochrome oxidase metabolism of acetaminophen is responsible for hepatic necrosis
via acylation of hepatic tissue. The treatment of acetaminophen toxicity includes the use
of N-acetylcysteine (Mucomyst), which acts as a glutathione substitute. The risk of
hepatotoxicity is predicted with the Rumack-Matthew nomogram, which uses the hours
after ingestion and plasma acetaminophen level to predict the probability of
hepatotoxicity. Severe hepatotoxicity can be fatal.
According to the 2010 ADA guidelines, HbA1C percent can be used as an assay to
diagnose diabetes.
True/False - correct answerT;
The 2010 ADA Clinical Practice Recommendations added measurement of HbA1C as a
diagnostic assay for diagnosis of diabetes.
Which of the following conditions would make a sample unsuitable for lactic acid
testing?
Choose the single best answer
A. Movement of hand or arm during specimen collection
B. Received in the lab on ice
C. Centrifuged in a refrigerated centrifuge
D. Specimen centrifuged and plasma separated from cells less than 15 minutes after
collection - correct answerA;
Movement of the muscles in the hand or arm during specimen collection will falsely
increase lactic acid concentration. A blood sample for lactic acid testing should be
,placed on ice immediately after collection, centrifuged within 15 minutes of collection,
and plasma immediately separated from cells following centrifugation. If possible, a
refrigerated centrifuge should be used.
You are working in a clinical chemistry laboratory and are analyzing a plasma glucose
sample. The sample is flagged by the analyzer for being "outside of linear range." You
manually dilute the sample 1:2 and rerun it. Again, you receive an "outside linear range"
alert. You decide to perform a different manual dilution. This time you manually dilute
the original sample again; this time using a 1:3 dilution. The instrument gives you a
glucose value of 150 mg/dL from this diluted sample. What is the actual patient glucose
result that you should report to the physician?
Choose the single best answer
A. 100 mg/dL
B. 400 mg/dL
C. 600 mg/dL
D. 450 mg/dL
E. 1200 mg/dL - correct answerD;
The correct response is option D: 450 mg/dl. A 1:3 dilution entails mixing one part
patient sample with two parts diluent, for a total volume of 3 parts. In laboratory
dilutions, the total volume is considered a dilution factor. The dilution factor in this
question is 3. So a diluted sample with a value of 150 would need to be multiplied by 3
to obtain the correct final answer. 150 x 3 = 450 mg/dl.
That portion of an enzyme which is separated from its cofactor is called a(n):
Choose the single best answer
A. Partial enzyme
B. Isoenzyme
C. Coenzyme
D. Apoenzyme - correct answerD;
A partial enzyme is not an actual term used in the laboratory. An isoenzyme is a related
enzyme with a different chemical structure. Finally, a coenzyme is a non-protein
molecule (often a vitamin) that helps an enzyme become active.
A low CSF glucose level is associated with all the following except:
Choose the single best answer
A. Hyperglycemia
B. Fungal meningitis
C. Toxoplasmosis
D. Hypoglycemia - correct answerA;
, In hyperglycemia you would expect a normal or elevated CSF glucose level- this
question is asking where you would expect to see a decreased (low) CSF glucose level,
and in this case hyperglycemia would be the one condition that is excluded (therefore
the correct answer).
Blood lactic acid concentration is an indicator of impaired circulation and tissue
oxygenation in critically ill patients. If circulation and tissue oxygenation are impaired,
blood lactic acid concentration will decrease below the lower end of the established
reference range.
True/False - correct answerFalse;
Lactic acid will increase. When cells do not receive enough oxygen because they are
not receiving enough blood, they release excess lactic acid into the bloodstream. Organ
failure as a result of septic shock may be indicated by unexplained metabolic acidosis
(low blood pH and low bicarbonate level) and extremely elevated lactic acid, where
blood pH is <7.30 and plasma lactic acid is >1.5 times the upper limit of the laboratory's
established reference values.
When should blood samples for trough drug levels be collected?
Choose the single best answer
A. 30 minutes after peak levels
B. 45 minutes before the next dose
C. 1-2 hours after the last dose
D. immediately before the next dose is given - correct answerD;
The trough drug level is drawn immediately before the next dose is given as the drug
level is expected to be the lowest in the body at this point.
Which of the following contributes to specific gravity but does NOT contribute to
osmolality?
Choose the single best answer
A. protein
B. NaCl
C. urea
D. glucose - correct answerA;
The presence of large amounts of protein and glucose will alter the specific gravity and
should be considered when interpreting specific gravity results. Osmolality measures
the analytes in the following equation- note that protein is not included in the calculation
of osmolality. Osmolality = 1.86 Na + (Glucose/18) + (BUN/2.8) + 9 (or) 1.91 Na +
(Glucose/15) + (BUN/2.25).
Which of the following is true of genotype screening in pharmacogenomics?
Questions With Correct Answers
Latest Update 2025/2026 GRADED A+
Which one of the following statements about acetaminophen metabolism is false?
Choose the single best answer
A. It is metabolized in the kidney
B. It is largely metabolized in the liver to glucuronide and sulfonate conjugates
C. A small amount is metabolized via cytochrome oxidase to a reactive
benzoquinoneimine intermediate
D. This intermediate becomes toxic to the liver once tissue glutathione becomes
depleted - correct answerA;
The benzoquinoneimine intermediate produced in the liver as a result of hepatic
cytochrome oxidase metabolism of acetaminophen is responsible for hepatic necrosis
via acylation of hepatic tissue. The treatment of acetaminophen toxicity includes the use
of N-acetylcysteine (Mucomyst), which acts as a glutathione substitute. The risk of
hepatotoxicity is predicted with the Rumack-Matthew nomogram, which uses the hours
after ingestion and plasma acetaminophen level to predict the probability of
hepatotoxicity. Severe hepatotoxicity can be fatal.
According to the 2010 ADA guidelines, HbA1C percent can be used as an assay to
diagnose diabetes.
True/False - correct answerT;
The 2010 ADA Clinical Practice Recommendations added measurement of HbA1C as a
diagnostic assay for diagnosis of diabetes.
Which of the following conditions would make a sample unsuitable for lactic acid
testing?
Choose the single best answer
A. Movement of hand or arm during specimen collection
B. Received in the lab on ice
C. Centrifuged in a refrigerated centrifuge
D. Specimen centrifuged and plasma separated from cells less than 15 minutes after
collection - correct answerA;
Movement of the muscles in the hand or arm during specimen collection will falsely
increase lactic acid concentration. A blood sample for lactic acid testing should be
,placed on ice immediately after collection, centrifuged within 15 minutes of collection,
and plasma immediately separated from cells following centrifugation. If possible, a
refrigerated centrifuge should be used.
You are working in a clinical chemistry laboratory and are analyzing a plasma glucose
sample. The sample is flagged by the analyzer for being "outside of linear range." You
manually dilute the sample 1:2 and rerun it. Again, you receive an "outside linear range"
alert. You decide to perform a different manual dilution. This time you manually dilute
the original sample again; this time using a 1:3 dilution. The instrument gives you a
glucose value of 150 mg/dL from this diluted sample. What is the actual patient glucose
result that you should report to the physician?
Choose the single best answer
A. 100 mg/dL
B. 400 mg/dL
C. 600 mg/dL
D. 450 mg/dL
E. 1200 mg/dL - correct answerD;
The correct response is option D: 450 mg/dl. A 1:3 dilution entails mixing one part
patient sample with two parts diluent, for a total volume of 3 parts. In laboratory
dilutions, the total volume is considered a dilution factor. The dilution factor in this
question is 3. So a diluted sample with a value of 150 would need to be multiplied by 3
to obtain the correct final answer. 150 x 3 = 450 mg/dl.
That portion of an enzyme which is separated from its cofactor is called a(n):
Choose the single best answer
A. Partial enzyme
B. Isoenzyme
C. Coenzyme
D. Apoenzyme - correct answerD;
A partial enzyme is not an actual term used in the laboratory. An isoenzyme is a related
enzyme with a different chemical structure. Finally, a coenzyme is a non-protein
molecule (often a vitamin) that helps an enzyme become active.
A low CSF glucose level is associated with all the following except:
Choose the single best answer
A. Hyperglycemia
B. Fungal meningitis
C. Toxoplasmosis
D. Hypoglycemia - correct answerA;
, In hyperglycemia you would expect a normal or elevated CSF glucose level- this
question is asking where you would expect to see a decreased (low) CSF glucose level,
and in this case hyperglycemia would be the one condition that is excluded (therefore
the correct answer).
Blood lactic acid concentration is an indicator of impaired circulation and tissue
oxygenation in critically ill patients. If circulation and tissue oxygenation are impaired,
blood lactic acid concentration will decrease below the lower end of the established
reference range.
True/False - correct answerFalse;
Lactic acid will increase. When cells do not receive enough oxygen because they are
not receiving enough blood, they release excess lactic acid into the bloodstream. Organ
failure as a result of septic shock may be indicated by unexplained metabolic acidosis
(low blood pH and low bicarbonate level) and extremely elevated lactic acid, where
blood pH is <7.30 and plasma lactic acid is >1.5 times the upper limit of the laboratory's
established reference values.
When should blood samples for trough drug levels be collected?
Choose the single best answer
A. 30 minutes after peak levels
B. 45 minutes before the next dose
C. 1-2 hours after the last dose
D. immediately before the next dose is given - correct answerD;
The trough drug level is drawn immediately before the next dose is given as the drug
level is expected to be the lowest in the body at this point.
Which of the following contributes to specific gravity but does NOT contribute to
osmolality?
Choose the single best answer
A. protein
B. NaCl
C. urea
D. glucose - correct answerA;
The presence of large amounts of protein and glucose will alter the specific gravity and
should be considered when interpreting specific gravity results. Osmolality measures
the analytes in the following equation- note that protein is not included in the calculation
of osmolality. Osmolality = 1.86 Na + (Glucose/18) + (BUN/2.8) + 9 (or) 1.91 Na +
(Glucose/15) + (BUN/2.25).
Which of the following is true of genotype screening in pharmacogenomics?
