Molecular Tests: Quality Assurance / Quality Control

· notes from AMP Molecular Diagnostic Assay Validation document (2009)

· controls included in each assay, when appropriate:

· positive

· negative (may be excluded when the majority of patients being tested are negative)

· should contain other nucleic acid targets that would be expected to be present in the patient sample

· normal controls not needed for sequencing assays, since reference sequence is known)

· blank

· contains the complete reaction mixture EXCEPT nucleic acids

· failure of any of the controls invalidates the run, and repeating the entire run should be considered

· internal nucleic acid target - amplification is recommended (either endogenous or spiked) to ensure that inhibitors are not interfering with the assay

· standards should be used in each run:

· e.g., size markers

· may be prudent to perform an external positive control to permit analysis of trends and to assess variation of non-kit-based controls over time

· calibration of instruments should be maintained

· preventative maintenance of instruments, routinely

· e.g., thermocyclers, pipettes, etc

· reagent lot testing

· test side-by-side with old reagent prior to implementation

· proficiency testing

· national testing programs (e.g., CAP) for all tests performed

· if none offered, participate in an alternative assessment at least twice per year (per CLSI)

· interlaboratory exchange is preferable

· CAP has a sample exchange registry

· technologist competency assessment

· documentation

· results of validation studies kept until at least 2 years after protocol is retired

· reporting

· reflect the reason for referral

· lab director confirm pre-written interpretations

· percentage of positive reactions, review (normal and abnormal results)

· TAT reviews

· Rejected specimens reviews

· Quality Improvement Project(s), annual

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References:

· Molecular Diagnostic Assay Validation. Association for Molecular Pathology Clinical Practice Committee (Oct. 2009)

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