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My simple rule of thumb for PCR related technologies is to check what, if anything, Stephen Bustin has to say about them. In 2013, Bustin’s team published* detailed minimal guidelines they consider necessary for publishing digital PCR studies. This indicates to me that digital PCR is on the cusp of becoming mainstream else why would Bustin publish guidelines for how to generate and report digital PCR data? That said, there are a few generalizations that apply for what it could take for digital PCR to go mainstream. Let’s explore some of them.

Context #1: As did qPCR, new technologies take years to become mainstream
qPCR itself took many years to become mainstream. The lab I was in at NIH was one of the first ones on campus to get a Taqman PCR machine in 1997. Fast forward to 2002-2003 and yet qPCR was still new enough that I was part of a group that used to go teach Eli Lilly scientists wet-lab qPCR basics at their campus in Indianapolis. Why does it take time for certain technology to become mainstream?

Context #2: Defined platforms and protocols, simplified data analysis
These are key criteria for technology to translate from R&D to clinic. Translation to clinic in turn is key for a technology to go mainstream. With two competing platforms (chip- or droplet-based), and as-yet relatively complicated protocols and data analysis, digital PCR is not there yet.

As it works its way into the standard lab tool-kit, digital PCR may yet emerge as an adjunct to qPCR, helping define and validate qPCR calibrators, especially in commercial kits and for detecting difficult rare mutations. After all, qPCR reference standards are its well-known Achilles heel, a weakness that does not plague digital PCR since it performs absolute quantification.

Context #3: Digital PCR is entering the picture when NGS (Next Generation Sequencing) is concurrently upending the molecular technologies landscape
This context is certainly different between qPCR and digital PCR. When qPCR came on the scene in the late 1990s, it could fill an existing gap in terms of accuracy (both specificity and sensitivity improved greatly) and quantification (several log folds greater dynamic range). Digital PCR comes on the scene at the same time as NGS (Next Generation Sequencing). Open question is if and when NGS becomes routine in all kinds of labs, especially in clinics, and for all kinds of applications such as screening, diagnostics, monitoring and nucleic acid quantification. This ambiguity regarding NGS creates space for digital PCR to take hold.

* Huggett, Jim F., et al. “The digital MIQE guidelines: minimum information for publication of quantitative digital PCR experiments.” Clinical chemistry59.6 (2013): 892-902. Page on clinchem.org