Quality Control (QC)
Definition
The day-to-day activities that verify a single batch of results is reliable: method blanks, certified-reference-material runs, duplicate injections, spike recoveries and control-chart plotting. QC is what you do at the bench every shift.
- Core QC techniques
- Method blanks, certified-reference-material runs, duplicate injections, spike recoveries, control-chart plotting
- QC timing
- Day-to-day bench activities, checked every shift
- QC scope
- Batch-level and case-specific verification, not whole-lab oversight
Common questions
What's the difference between quality control and quality assurance in a forensic lab?+
Quality control (QC) is the hands-on work done at the bench every shift, like running method blanks and duplicate injections to verify each batch of results. Quality assurance is the bigger system that oversees whether the lab's processes meet standards overall. QC is the daily reality; QA is the framework that ensures QC actually happens and works.
What counts as quality control in a forensic test?+
QC includes method blanks, certified-reference-material runs, duplicate injections, spike recoveries, and control-chart plotting. These techniques verify that a single batch of results is reliable. QC is corrective and case-specific, so labs adjust it based on what they find during testing.
Why do forensic labs run method blanks and duplicates?+
Blanks catch contamination or interference from the test method itself. Duplicates show whether results are reproducible. Together, they prove that the test procedure is working as it should for that particular batch of samples, which is what QC is really about.
Related terms
- ISO/IEC 17025:2017
- The international standard specifying general requirements for the competence of testing and calibration laboratories. Covers management (document control, non-conforming work, audits) and...
- NABL
- National Accreditation Board for Testing and Calibration Laboratories, a constituent board of the Quality Council of India. It is the sole accrediting...
- Quality Assurance (QA)
- The management system that ensures QC actually happens and stays effective over time: written SOPs, training and competence records, internal audits, document...
- Accreditation
- Formal recognition by a standards body (such as UKAS in the UK, A2LA in the US, or NABL in India) that a...
- Calibration
- A steganalysis technique that estimates the cover image statistics by cropping or decompressing and re-compressing the test image to produce a reference....
- Certified Reference Material (CRM)
- A sample with one or more analyte concentrations established by an accredited body and traceable to a national metrology institute. NIST SRM...
- ISO 9001
- The international standard for quality management systems published by the International Organization for Standardization. Certification means the organisation has documented and implemented...
- Measurement Uncertainty (MU)
- A quantified parameter associated with a result that characterises the dispersion of values reasonably attributable to the measurand. Estimated by the GUM...
- Proficiency Testing (PT)
- A quality assurance mechanism in which laboratories analyse blind samples distributed by an external scheme coordinator and have their results compared against...
- SWGDOC and Other SWGs
- Scientific Working Groups (SWGDOC for questioned documents, SWGDRUG for drugs, SWGSTAIN for bloodstain, SWGFEX for fire and explosion, SWGFAST for fingerprints) that...
- Traceability and Uncertainty
- Metrological traceability is an unbroken chain of calibrations linking a result to a stated reference (CRM, NPL India primary standard, NIST). Measurement...
- Validation
- The process of establishing through systematic testing that a method does what it claims to do, within defined conditions and with a...
Explained in these topics
- ISO 17025 and Quality Management in Forensic LaboratoriesThe day-to-day activities that verify a single batch of results is reliable: method blanks, certified-reference-material runs, duplicate injections, spike reco...
- Quality Control Management in Forensic InstitutionsOperational, sample-level techniques used to fulfil quality requirements: blanks, controls, duplicates, calibration checks, chart limits. QC is corrective and...