The COVID era exposed a diagnostic failure that can no longer be ignored: PCR-based testing is not a true “gold standard” for clinical infection diagnosis. PCR is widely treated as definitive, but mechanistically it is not an identification method—it is an amplification step that simply makes more copies of genetic material. The real weakness comes from what many systems use after amplification: probe-based fluorescence detection, which generates a “signal” without actually confirming what is present. That is how medicine ends up with false positives, misclassification, and policy decisions built on unstable data.
In my interview with Dr. Roger Hodkinson—a highly respected pathologist and Chairman of MultiSeq—he explains why the PCR problem is structural: probe-based testing functions like a “lock-and-key,” where partial matches can still trigger a positive signal. Even worse, infectious syndromes (cough/cold, diarrhea, suspected STI) are rarely caused by only one organism—yet most PCR workflows are narrow, slow, and often treated as confirmatory when they’re not. In practice, clinicians are forced into an “educated guess” model because results frequently come back days later and only cover a limited scope.
MultiSeq is attempting to replace this entire model with something fundamentally different: sequence-confirmed diagnosis. Instead of relying on probe fluorescence to “suggest” identity, it uses modified Sanger sequencing to directly read the nucleotide sequence and confirm which pathogen is actually present. Traditional Sanger sequencing is widely recognized as a gold-standard method because it produces a verifiable sequence output (an electropherogram), but historically it was too limited for real-world diagnostics because it could only handle one target per test. MultiSeq’s central claim is that its approach enables multiplex Sanger sequencing—meaning it can generate confirmatory sequences for multiple pathogens from a single patient sample at the same time.
Dr. Hodkinson also highlights a major vulnerability in molecular testing: cross-contamination. Opening sample tubes can generate aerosols that contaminate other samples, driving additional false positives. MultiSeq describes an internal “bar-code”–style approach designed to detect this kind of contamination, strengthening confidence that a reported pathogen truly came from that patient’s specimen.
The bottom line is simple: a flawed testing foundation produces flawed medicine and flawed policy. PCR has been misused as a confirmatory diagnostic standard. If a sequencing-confirmation platform like MultiSeq can be validated and scaled for real clinical throughput, it could represent a substantial upgrade in infectious disease diagnostics and potentially help correct the damage caused by years of overreliance on non-confirmatory testing.
You can learn more here: https://multiseq.bio
You can contact Dr. Roger Hodkinson on his email here: roger@multiseq.ca
