# Next Generation Infectious Disease Diagnostics: Microfluidic-Free Gigapixel PCR with Self-Assembled Partitioning

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2023 · $623,700

## Abstract

ABSTRACT
Infections by different pathogens can manifest with similar symptoms, but appropriate treatment requires specific
and accurate diagnosis. Clinicians often turn to multiplexed assays testing for many organisms (e.g. BioFire).
While these approaches can test for 50-70 organisms, they do not provide concentration titers, which is
necessary to identify the causative pathogen among the several false positives or clinically meaningless
commensals. As a result, the clinician must perform additional tests to identify which of the positives is causative.
Although these tests use quantitative PCR, in clinical labs the results are reported as presence/absence due to
the finicky nature of PCR in this setting, which is sensitive to minor variations in reaction efficiency, operator
variability. As a result, today, only a few widespread PCR tests are FDA approved to report quantitative result.
In contrast to qPCR, digital PCR (dPCR) measures target titers by counting individual molecules. As a result,
dPCR provides an absolute concentration measurement that doesn’t require a standard curve. In addition, the
reaction is cycled to endpoint, then quantified; it does not require careful estimation of the amplification rate,
which is a major source of variability in qPCR. Thus, dPCR is less sensitive to variations in reaction efficiency
and provides superior consistency. However, current dPCR methods are limited in multiplexing, allowing just 5-
6 targets per assay, while qPCR can test up to 100. Moreover, dPCR requires complex microfluidic equipment
that burdens testing lab personnel and increases cost. Until these issues can be addressed, qPCR will continue
to dominate the clinical lab, and quantitative and absolute pathogen load reporting will remain beyond reach.
Here, we propose a novel nucleic acid technology combining the quantitativeness and robustness of dPCR with
the simplicity and multiplexing of qPCR. Our vision is to enable broad spectrum detection wherein each pathogen
is associated with a high confidence, quantitative titer. Our approach – gigapixel PCR (gPCR) – is enabled by
our recent discoveries of self-assembled partitioning, for microfluidic-free generation of monodispersed
emulsions, and linearized target quantitation with capillary electrophoresis (CE). CE allows sensitive quantitation
over 7 decades and provides amplicon length information with single nucleotide resolution. In gPCR, we use this
to perform multiplexed detection of over 100 amplicons per reaction. In contrast to qPCR, which requires that
the sample be split to test for different targets, thereby diluting it and reducing sensitivity, with gPCR the targets
are tested without splitting, maintaining them at maximal concentration, and substantially increasing sensitivity.
Moreover, based on robust dPCR, gPCR provides reproducible, quantitative results across testing conditions. It
thus addresses the major limitations of current dPCR technologies and provides the first viable...

## Key facts

- **NIH application ID:** 10682295
- **Project number:** 1R01AI176829-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Adam R. Abate
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $623,700
- **Award type:** 1
- **Project period:** 2023-06-15 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10682295

## Citation

> US National Institutes of Health, RePORTER application 10682295, Next Generation Infectious Disease Diagnostics: Microfluidic-Free Gigapixel PCR with Self-Assembled Partitioning (1R01AI176829-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10682295. Licensed CC0.

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