AACC AACC Laboratory Instrumentation & Technology 3

Question 1

What is the purpose of a Levy-Jennings chart in laboratory instrumentation monitoring?

Accepted Answer

To graphically track QC values and detect systematic or random error trends

Answer

To plot patient result distributions over time

Answer

To schedule instrument maintenance intervals

Answer

To compare reagent lot performance across vendors

Question 2

In clinical immunoassays, what does the 'hook effect' (prozone phenomenon) cause?

Accepted Answer

Falsely low results at very high analyte concentrations due to antigen excess

Answer

False elevation of analyte due to cross-reactivity

Answer

Non-specific binding of the label to the solid phase

Answer

Interference from hemolyzed samples

Question 3

Which type of analyzer configuration processes one test at a time on a single patient sample?

Accepted Answer

Discrete analyzer

Answer

Continuous flow analyzer

Answer

Centrifugal analyzer

Answer

Batch analyzer

Question 4

What is the main advantage of using tandem mass spectrometry (MS/MS) over single-stage MS in clinical newborn screening?

Accepted Answer

Ability to simultaneously quantify multiple analytes with high specificity in one run

Answer

Lower instrument cost

Answer

Simpler sample preparation requirements

Answer

Longer column lifetime

Question 5

What type of interference is caused by lipemia in photometric assays?

Accepted Answer

Optical interference due to light scattering by lipid particles

Answer

Chemical interference altering the reaction pathway

Answer

Electrochemical interference with ISE measurements

Answer

Immunological cross-reactivity with antibody reagents

Question 6

In nephelometry used for protein quantification, what is being measured?

Accepted Answer

Light scattered at an angle by antigen-antibody aggregates

Answer

Light absorbed by the antigen-antibody complex

Answer

Fluorescence emitted after laser excitation

Answer

Electrical impedance change caused by immune complexes