Evidence map›Paper›PMID 42144491›Full record

ArticleAnnals of biomedical engineering2026

A Droplet Digital PCR Assay for Quantification of Bacteriophage Viral Vector Titer and Purity.

Peter J Voorhees, Ronni M Ponek, Jamie D Liu, Samuel K Lai

Abstract read
PubMed Publisher
In one paragraph

Article in Annals of biomedical engineering, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

4 authors.

Peter J VoorheesDivision of Pharmacoengineering and Molecular Pharmaceutics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Ronni M PonekDepartment of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Jamie D LiuDepartment of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Samuel K LaiDivision of Pharmacoengineering and Molecular Pharmaceutics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. lai@unc.edu.ORCID http://orcid.org/0000-0001-5293-9296

Funding

David and Lucile Packard Foundation 2013-39274Division of Intramural Research, National Institute of Allergy and Infectious Diseases R21AI185808NIDDK NIH HHS DK007737-30
6 · The paper itself

Abstract

purposeBacteriophage (phage)-based vectors offer considerable promise as tools for tuning the microbiome with molecular and genetic precision. However, standardized methods to rigorously characterize phage vectors remain lacking. Here, we present an optimized digital droplet PCR (ddPCR)-based assay for quantifying both the purity and potency of phage vector preparations.

methodsWe utilized central composite design to develop a ddPCR assay capable of quantifying the number of phage vector capsids packed with the phage vector genome or packed with the transgenic DNA of interest. This assay targets 2 unique DNA barcodes, designed to be biologically inert and maximally orthogonal to existing DNA sequences.

resultsThrough stringent optimization, we were able to achieve assay conditions that enable a dynamic range of nearly 3 orders of magnitude and correct for systemic error in the assay. We then show that biological activity assays consistently underestimate transgene-packed vector titers, leading to overestimation of true transduction efficiency, particularly when contamination by genome-packed vectors is high. We further demonstrate how this approach facilitates optimization of vector production conditions and substantially improves the precision and reproducibility of phage vector transduction.

conclusionCompared to assays of biological activity, this optimized ddPCR assay has improved accuracy and, through design of experiments optimization, high precision (CVs = 5.5 ± 1.3% and 4.5 ± 1.0% for the genome and transgene barcodes, respectively). This assay can be broadly adopted to characterize and quality control vector preparations for various applications.

Indexed as

Assay optimizationddPCRMicrobiomePhageQuality controlViral vector quantification

Identifiers

PMID42144491

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.