AMT MLS EXAM NEWEST
Question: A laboratory receives a serum specimen for potassium testing
that is visibly hemolyzed. What is the most likely effect on the
potassium result?
A. Falsely decreased potassium concentration
B. Falsely increased potassium concentration
C. No effect on potassium concentration
D. Complete elimination of potassium from the specimen
Correct Answer: B. Falsely increased potassium concentration
Rationale: Hemolysis releases intracellular contents from red blood
cells into the serum or plasma. Because potassium is present at a much
higher concentration inside cells than in extracellular fluid, hemolysis
can cause an artificially elevated measured potassium result. The
laboratory should assess specimen acceptability and follow its
established procedures regarding recollection or reporting when
significant hemolysis may interfere with testing.
Question: Which quality control rule is primarily designed to detect
random error?
A. 10x rule
B. 2₂s rule
C. R₄s rule
D. 4₁s rule
Correct Answer: C. R₄s rule
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, AMT MLS EXAM NEWEST
Rationale: The R₄s rule identifies a difference of four standard
deviations between two control measurements within the same run,
which is commonly associated with random error. Random error may
result from factors such as pipetting variation, unstable
instrumentation, or other unpredictable analytical problems.
Recognition of random error helps laboratory personnel investigate
issues before patient results are released.
Question: Which agency establishes standards for laboratory testing
performed on human specimens in the United States under the Clinical
Laboratory Improvement Amendments?
A. OSHA
B. CMS
C. FDA
D. CDC
Correct Answer: B. CMS
Rationale: The Centers for Medicare & Medicaid Services administers
CLIA requirements for laboratories performing testing on human
specimens. CLIA establishes quality standards intended to help ensure
the accuracy, reliability, and timeliness of laboratory test results.
Laboratory professionals must understand how regulatory requirements
affect testing procedures, personnel qualifications, quality systems, and
laboratory operations.
Question: What is the primary purpose of a Safety Data Sheet (SDS)?
A. To provide information about chemical hazards and safe handling
B. To record daily patient test results
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, AMT MLS EXAM NEWEST
C. To document employee attendance
D. To establish reference intervals
Correct Answer: A. To provide information about chemical hazards
and safe handling
Rationale: A Safety Data Sheet contains important information about a
chemical substance, including its hazards, handling requirements,
storage recommendations, personal protective equipment, emergency
procedures, and other safety information. Laboratory personnel should
know how to access and interpret SDS information to reduce the risk of
chemical exposure and respond appropriately to hazardous incidents.
Question: A control result exceeds the laboratory's acceptable limits.
What should be done before patient results are reported?
A. Report the patient results because the instrument completed the run
B. Investigate the control failure according to laboratory procedure
C. Delete the control result and continue testing
D. Average the control result with the previous day's value
Correct Answer: B. Investigate the control failure according to
laboratory procedure
Rationale: An out-of-range control result indicates that the analytical
process may not be performing as expected. The laboratory should
investigate the cause before releasing affected patient results. Possible
areas for investigation include reagent integrity, calibration status,
instrument performance, control preparation, environmental
conditions, and procedural errors. Patient results should only be
reported when acceptable quality requirements have been met.
Page 3 of 92
, AMT MLS EXAM NEWEST
Question: What is the primary function of a centrifuge in the clinical
laboratory?
A. To separate components of a specimen according to density through
centrifugal force
B. To measure the absorbance of light
C. To determine the pH of a solution
D. To identify bacterial species
Correct Answer: A. To separate components of a specimen according
to density through centrifugal force
Rationale: Centrifugation applies centrifugal force to separate
components of a specimen based on differences in density. For
example, centrifugation can separate serum or plasma from cellular
components of blood. Proper centrifugation time, speed, specimen
balance, and tube handling are important because improper
centrifugation can affect specimen quality and analytical results.
Question: A spectrophotometer measures the amount of light that is:
A. Produced by a specimen
B. Absorbed by a substance at a selected wavelength
C. Reflected only from the outside of a tube
D. Generated by a centrifuge
Correct Answer: B. Absorbed by a substance at a selected wavelength
Rationale: Spectrophotometry measures the interaction between light
and a substance. Many clinical chemistry methods determine analyte
concentration by measuring the amount of light absorbed at a specific
wavelength. The measured absorbance is related to the concentration
Page 4 of 92
Question: A laboratory receives a serum specimen for potassium testing
that is visibly hemolyzed. What is the most likely effect on the
potassium result?
A. Falsely decreased potassium concentration
B. Falsely increased potassium concentration
C. No effect on potassium concentration
D. Complete elimination of potassium from the specimen
Correct Answer: B. Falsely increased potassium concentration
Rationale: Hemolysis releases intracellular contents from red blood
cells into the serum or plasma. Because potassium is present at a much
higher concentration inside cells than in extracellular fluid, hemolysis
can cause an artificially elevated measured potassium result. The
laboratory should assess specimen acceptability and follow its
established procedures regarding recollection or reporting when
significant hemolysis may interfere with testing.
Question: Which quality control rule is primarily designed to detect
random error?
A. 10x rule
B. 2₂s rule
C. R₄s rule
D. 4₁s rule
Correct Answer: C. R₄s rule
Page 1 of 92
, AMT MLS EXAM NEWEST
Rationale: The R₄s rule identifies a difference of four standard
deviations between two control measurements within the same run,
which is commonly associated with random error. Random error may
result from factors such as pipetting variation, unstable
instrumentation, or other unpredictable analytical problems.
Recognition of random error helps laboratory personnel investigate
issues before patient results are released.
Question: Which agency establishes standards for laboratory testing
performed on human specimens in the United States under the Clinical
Laboratory Improvement Amendments?
A. OSHA
B. CMS
C. FDA
D. CDC
Correct Answer: B. CMS
Rationale: The Centers for Medicare & Medicaid Services administers
CLIA requirements for laboratories performing testing on human
specimens. CLIA establishes quality standards intended to help ensure
the accuracy, reliability, and timeliness of laboratory test results.
Laboratory professionals must understand how regulatory requirements
affect testing procedures, personnel qualifications, quality systems, and
laboratory operations.
Question: What is the primary purpose of a Safety Data Sheet (SDS)?
A. To provide information about chemical hazards and safe handling
B. To record daily patient test results
Page 2 of 92
, AMT MLS EXAM NEWEST
C. To document employee attendance
D. To establish reference intervals
Correct Answer: A. To provide information about chemical hazards
and safe handling
Rationale: A Safety Data Sheet contains important information about a
chemical substance, including its hazards, handling requirements,
storage recommendations, personal protective equipment, emergency
procedures, and other safety information. Laboratory personnel should
know how to access and interpret SDS information to reduce the risk of
chemical exposure and respond appropriately to hazardous incidents.
Question: A control result exceeds the laboratory's acceptable limits.
What should be done before patient results are reported?
A. Report the patient results because the instrument completed the run
B. Investigate the control failure according to laboratory procedure
C. Delete the control result and continue testing
D. Average the control result with the previous day's value
Correct Answer: B. Investigate the control failure according to
laboratory procedure
Rationale: An out-of-range control result indicates that the analytical
process may not be performing as expected. The laboratory should
investigate the cause before releasing affected patient results. Possible
areas for investigation include reagent integrity, calibration status,
instrument performance, control preparation, environmental
conditions, and procedural errors. Patient results should only be
reported when acceptable quality requirements have been met.
Page 3 of 92
, AMT MLS EXAM NEWEST
Question: What is the primary function of a centrifuge in the clinical
laboratory?
A. To separate components of a specimen according to density through
centrifugal force
B. To measure the absorbance of light
C. To determine the pH of a solution
D. To identify bacterial species
Correct Answer: A. To separate components of a specimen according
to density through centrifugal force
Rationale: Centrifugation applies centrifugal force to separate
components of a specimen based on differences in density. For
example, centrifugation can separate serum or plasma from cellular
components of blood. Proper centrifugation time, speed, specimen
balance, and tube handling are important because improper
centrifugation can affect specimen quality and analytical results.
Question: A spectrophotometer measures the amount of light that is:
A. Produced by a specimen
B. Absorbed by a substance at a selected wavelength
C. Reflected only from the outside of a tube
D. Generated by a centrifuge
Correct Answer: B. Absorbed by a substance at a selected wavelength
Rationale: Spectrophotometry measures the interaction between light
and a substance. Many clinical chemistry methods determine analyte
concentration by measuring the amount of light absorbed at a specific
wavelength. The measured absorbance is related to the concentration
Page 4 of 92
