AACC AACC Laboratory Instrumentation & Technology

Question 1

Which detector is most commonly used in high-performance liquid chromatography (HPLC) for measuring UV-absorbing analytes in clinical chemistry?

Accepted Answer

UV-Vis spectrophotometric detector

Answer

Flame ionization detector

Answer

Thermal conductivity detector

Answer

Electron capture detector

Question 2

What is the primary purpose of an internal standard in mass spectrometry-based clinical assays?

Accepted Answer

To correct for ion suppression and instrument variability

Answer

To increase sample volume

Answer

To serve as a positive control

Answer

To calibrate the column temperature

Question 3

In a clinical chemistry analyzer, what does a reagent blank correct for?

Accepted Answer

Absorbance contributed by the reagent itself

Answer

Patient sample turbidity

Answer

Hemolysis interference

Answer

Calibrator drift over time

Question 4

Which ionization technique is considered 'soft' and is commonly used for large biomolecules in clinical mass spectrometry?

Accepted Answer

Electrospray ionization (ESI)

Answer

Electron ionization (EI)

Answer

Chemical ionization (CI)

Answer

Fast atom bombardment (FAB)

Question 5

What is carryover in automated clinical analyzers?

Accepted Answer

Contamination of one sample by a preceding high-concentration sample

Answer

A QC failure mode due to reagent expiration

Answer

Evaporation of calibrator solutions

Answer

Bubble formation in the reaction cuvette

Question 6

In flow cytometry used in clinical laboratories, what physical property is measured by the side scatter (SSC) signal?

Accepted Answer

Cell granularity and internal complexity

Answer

Cell size

Answer

Surface antigen expression

Answer

DNA content