CLC Instrumentation & Technology Applications 2

Question 1

Which detection principle do most modern hematology analyzers use to differentiate cell populations by size?

Accepted Answer

Electrical impedance (Coulter principle)

Answer

Modern hematology analyzers primarily use electrical impedance (Coulter principle), measuring the change in electrical resistance as cells pass through an aperture.

Question 2

In mass spectrometry-based clinical assays, what does the term 'internal standard' most directly address?

Accepted Answer

Matrix effects and extraction variability

Answer

An internal standard, typically a stable isotope-labeled analog of the analyte, compensates for matrix effects and variability introduced during sample preparation and extraction.

Question 3

A laboratory consultant evaluating a new automated coagulation analyzer notes it uses clot-based detection. Which physical principle underlies this method?

Accepted Answer

Change in optical absorbance or turbidity as fibrin forms

Answer

Clot-based coagulation analyzers detect fibrin clot formation by monitoring the increase in optical turbidity or the change in absorbance as the clot develops.

Question 4

Which chromatographic technique is most commonly used in clinical laboratories for therapeutic drug monitoring via LC-MS/MS?

Accepted Answer

Reversed-phase high-performance liquid chromatography (RP-HPLC)

Answer

Reversed-phase HPLC is the predominant separation technique paired with tandem mass spectrometry for therapeutic drug monitoring due to its versatility with small hydrophobic molecules.

Question 5

A laboratory's point-of-care blood gas analyzer produces a result that differs significantly from the central laboratory result on the same sample. Which factor is MOST likely responsible?

Accepted Answer

Pre-analytical differences including air bubble exposure and time delay

Answer

Blood gas values are highly sensitive to pre-analytical variables such as air bubble contamination, delay in analysis, and improper sample handling, which commonly explain POC vs. central lab discordance.

(CLC) Certified Laboratory Consultant Practice Test

(CLC) Certified Laboratory Consultant Practice Test

CLC Instrumentation & Technology Applications 2