MLS Quality & Safety 3

Question 1

A method validation study compares a new analyzer to a reference method using 40 patient samples. Which statistical analysis is used to assess proportional and constant bias?

Accepted Answer

Passing-Bablok or Deming regression

Answer

Passing-Bablok and Deming regression are used in method comparison studies to detect proportional and constant systematic errors between two methods.

Question 2

What is the purpose of running a blank in photometric assays?

Accepted Answer

To zero the instrument and eliminate background absorbance

Answer

The reagent blank zeroes the spectrophotometer to account for background absorbance from reagents, isolating the analyte's contribution.

Question 3

A laboratory's glucose linearity study shows acceptable results from 10–500 mg/dL but not above. What should be done for patient samples with glucose above 500 mg/dL?

Accepted Answer

Dilute the sample and multiply the result by the dilution factor

Answer

Samples exceeding the analytical measurement range must be diluted; results are then multiplied by the dilution factor to report an accurate value.

Question 4

The GHS (Globally Harmonized System) label on a chemical container includes a pictogram of a flame over a circle. This indicates the substance is:

Accepted Answer

An oxidizer

Answer

The GHS flame-over-circle pictogram specifically denotes oxidizing substances, which can intensify fires or cause spontaneous combustion.

Question 5

Which of the following is an example of a pre-analytical error affecting laboratory results?

Accepted Answer

Hemolysis due to traumatic venipuncture

Answer

Hemolysis from traumatic venipuncture is a pre-analytical error occurring before the sample reaches the analyzer, potentially falsely elevating potassium and LDH.

(MLS) Medical Laboratory Scientist Practice Test

(MLS) Medical Laboratory Scientist Practice Test

MLS Quality & Safety 3