# Enabling exosome biomarker development via digitized single vesicle analysis

> **NIH NIH R01** · UNIV OF MARYLAND, COLLEGE PARK · 2020 · $428,266

## Abstract

PROJECT SUMMARY/ABSTRACT
Exosomes represent the next “omic” frontier in diagnostic biomarkers. As such, numerous technologies have
been developed to exploit detection of exosomal proteins or microRNA (miRNA) cargo for potential biomarker
development. In general, these approaches are based on the assumption that detection of a particular
exosomal protein or miRNA profile will correlate with a specific disease. Yet, this assumption is undermined by
the inherent variability resulting from heterogeneity of exosome populations collected from biological fluids.
Further, previous attempts to develop protein and, especially, miRNA-based biomarkers have revealed that a
single miRNA sequence can be correlated with numerous diseases even without the confounding
heterogeneity of exosomes. Thus, we hypothesize that to achieve appropriate specificity for the discovery of
exosomal biomarkers, correlation of exosomal proteins and miRNAs – simultaneously detected and resolvable
at the single-exosome level – is necessary. Here we propose a highly dense multiplexed microsystem
implementing a new isothermal nucleic acid amplification method for digital exosome analysis, enabling the
specific correlation of membrane protein markers and miRNA sequences at the single exosome level. A low-
cost and easy-to-use thermoplastic chip with integrated amplification reagents enables self-discretization of
exosomes for spatially multiplexed analysis, scalable up to one million reactions. For specific detection of
miRNA sequences and membrane proteins, we have designed an isothermal reaction optimized for the
amplification of short DNA and RNA sequences that identifies miRNA sequences as well as DNA
oligonucleotides conjugated to antibodies that label the exosome surface proteins. The reaction, referred to as
transcription cycling amplification (TCA), utilizes DNA polymerase with exonuclease activity to degrade
donor/quencher-labeled probes (i.e., FRET probes) for specific and real-time quantitative detection. In tandem,
RNA polymerase acts on the polymerized oligo for the cyclical generation of RNA that leads to exponential
amplification, providing highly sensitive detection. By integrating these two tools, we will develop a biomarker
discovery platform that first digitizes the exosomes across a dense reaction array and correlates miRNA
sequences with membrane proteins in single exosomes.

## Key facts

- **NIH application ID:** 9857047
- **Project number:** 5R01GM130923-02
- **Recipient organization:** UNIV OF MARYLAND, COLLEGE PARK
- **Principal Investigator:** Don L DeVoe
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $428,266
- **Award type:** 5
- **Project period:** 2019-02-01 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9857047

## Citation

> US National Institutes of Health, RePORTER application 9857047, Enabling exosome biomarker development via digitized single vesicle analysis (5R01GM130923-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9857047. Licensed CC0.

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