MLSC 4053 Module 2 Lecture 4: Quality Measures in Molecular Diagnostics

This set of vocabulary flashcards covers quality assurance standards, specimen handling, storage requirements, laboratory controls, and reporting protocols in clinical molecular diagnostics.

Pre-analytical error

The consequence of erroneous or misleading results caused by events that occur prior to sample analysis.

Chain of custody

The process and documentation used for specimens in medicolegal situations or forensic work to ensure security and limited access.

WBC lysis

The breakdown of white blood cells which leads to a reduced yield of nucleic acids during molecular testing.

Tripotassium EDTA

An anticoagulant ($7.5-15\%$ solution) found in lavender-top tubes used for virology and molecular studies.

Acid citrate dextrose (ACD) solution

An anticoagulant additive found in yellow-top tubes used specifically for molecular biology.

FTA Paper

A specimen collection system where a sample is applied to a spot, dried, and a disc is punched out for reagent washes and PCR.

DNA Specimen Storage (Tissue)

Held for $<1\,\text{day}$ at $4^{\circ}C$, $>2\,\text{weeks}$ at $-20^{\circ}C$, or $>2\,\text{years}$ at $-70^{\circ}C$.

Isolated DNA Storage ($4^{\circ}C$)

Can be stored for $1-3\,\text{years}$, though Southern blot samples are limited to $1\,\text{year}$.

RNA Specimen Storage (Blood/Fluids)

Held for $<2\,\text{hours}$ at $23^{\circ}C$ or $4^{\circ}C$, or $5-7\,\text{days}$ in denaturant.

DEPC-treated water

A medium used to store isolated RNA for $<30\,\text{days}$ at $-20^{\circ}C$ or $-70^{\circ}C$.

Positive control

A quality control containing a known target nucleotide.

Negative control

A master mix with probes but no target DNA used to ensure there is no contamination.

Amplification (sensitivity) control

A control such as $\beta\text{-globin}$ that indicates the master mix is working correctly via a visible band.

Molecular ladder

A control used to verify that analyzed fragments are in the correct size range.

Thermocouples

Electronic thermometers used to check thermocyclers for cold spots.

Calibrators

Certified materials of known concentration used in real-time thermocyclers.

Test report

A document conveying the method/kit, locus, mutation/organism, analytical interpretation of raw data, and clinical interpretation.