Introduction: Why Quality Control Still Matters in the Cartridge Era

In the last decade, syndromic testing platforms like QIAstat-Dx®, BioFire® FilmArray®, and ePlex® have transformed how laboratories process infectious disease samples. With integrated extraction, amplification, and detection, these systems are marketed as “sample in, answer out.” But quality control (QC) remains a central requirement under CLIA, CDC, and international guidelines.

Quality control is the framework that ensures your reported results are reliable, reproducible, and defensible in audits. Whether you work in a clinical hospital lab, a university research core, or a public health setting, regulators expect clear documentation of how you validate and monitor each test.

For background on why QC is non-negotiable, see CDC’s CLIA overview, the CLIA Subpart K quality systems, and the CMS CLIA program site.

QIAstat-Dx: QC by Design

The QIAstat-Dx® Respiratory Panel uses an MS2 bacteriophage internal control built into every cartridge. If the control fails, the system invalidates the run. This design checks both extraction and amplification, giving the operator confidence that a negative result is not due to technical failure.

• EUA documentation: FDA QIAstat-Dx EUA Letter

• Performance standards: FDA SARS-CoV-2 Reference Panel

Still, QIAstat-Dx instructions for use recommend external positive and negative controls, which your laboratory defines in an Individualized Quality Control Plan (IQCP). For guidance, see CDC IQCP resources.

BioFire FilmArray: End-to-End Internal Controls

The BioFire® FilmArray® system takes another approach. Its pouches contain internal controls that monitor all stages of the run—from lysis to amplification. This built-in redundancy is why many users feel the system is “self-checking.”

• Documentation: BioFire RP2.1 IFU (FDA)

As with QIAstat-Dx, laboratories still need external QC material. CLIA requires controls at a frequency justified by risk assessment. For further reading, check CLIA PT rules and CMS proficiency testing program list.

ePlex: CLIA-Based Flexibility

The ePlex® Respiratory Pathogen Panel also incorporates process controls, but the system leaves external QC frequency to the laboratory, within the CLIA/IQCP framework.

• Documentation: FDA ePlex RP2 Fact Sheet

Here, lab directors must balance risk assessment with cost and workload. External positive controls can be expensive, but they remain the most defensible safeguard against drift in assay sensitivity.

Building a Defensible QC Strategy Across Platforms

1. Regulatory Foundations

• CLIA Subpart K (Quality Systems)

• CLIA Subpart M (Personnel Responsibilities)

• CDC Laboratory Systems Quality & Safety

• CDC Laboratory Quality Assurance Programs

These resources clarify why internal process controls are not enough. You need documented external QC, PT enrollment, and remedial action plans.

2. External Controls With Traceability

Using materials from NIST provides traceability and credibility:

• NIST SARS-CoV-2 RNA fragments (RGTM 10169)

• NIST SARS-CoV-2 research-grade material

• NIST SRM Program

• NIST SRM 2372a: Human DNA Quantitation Standard

3. Verification and Proficiency Testing

• FDA EUA molecular diagnostic tests list

• CMS: Proficiency Testing Programs

• 2025 Approved PT Programs (PDF)

4. Biosafety and Specimen Handling

• CDC Biosafety in Microbiological and Biomedical Laboratories (BMBL) 6th Edition (PDF)

• CDC COVID-19 Laboratory Biosafety Guidance

• CDC Specimen Collection Guidelines

• UC San Diego BSL Chart

• University of Illinois BSL-2 Guide (PDF)

5. Workforce Training and Informatics

• CDC OneLab Training

• CDC Laboratory Training Courses

• CDC LIMS Introduction Course

• CDC QMS Tools

Training ensures that staff understand not only how to operate the platform but also how QC integrates into the broader quality system.

Practical Tips for Lab Managers

• Rotate external controls across platforms: If you run both QIAstat-Dx and BioFire, coordinate control material use to minimize waste.

• Keep IQCP dynamic: Update whenever you switch cartridge lots or receive an FDA Field Safety Notice.

• Audit trails matter: Capture cartridge lot numbers, control results, and remedial actions in your LIMS.

• Don’t ignore basics: Even with cartridges, pipetting accuracy and biosafety level practices still determine result integrity.

For practical troubleshooting, see:

• UC Riverside qPCR Troubleshooting Guide

• Oregon State qPCR Guide (PDF)

• University of Puget Sound qPCR User Guide (PDF)

Conclusion

QIAstat-Dx, BioFire, and ePlex all embed internal process controls, but external QC, PT, biosafety, and training remain the lab’s responsibility. By anchoring QC to CLIA regulations, CDC training programs, and NIST reference materials, you build a workflow that not only satisfies auditors but also inspires confidence in clinicians who rely on your results.

In short: a cartridge can only do so much. True quality comes from people, policies, and proof that your lab can consistently deliver valid results.