# Biochemistry at single-cell resolution: a new approach to understand functional heterogeneity

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2023 · $626,680

## Abstract

Abstract
New methods to study heterogeneity at cellular resolution in complex tissues are
transforming our understanding of human biology and disease. These approaches
measure differences in gene expression, chromatin accessibility, and protein levels
across thousands to millions of cells to understand developmental trajectories of tissues,
tumors, and whole organisms. But these methods rely on measurements of static levels
of DNA, RNA, and proteins, and fail to capture dynamic biochemical activities that
underlie complex cellular functions. Instead of developing more direct readouts of
cellular function, the field has focused on inferring functional status from measurements
of mRNA abundance and chromatin accessibility in single cells. To accelerate the study
of biochemical heterogeneity among single cells, we developed functional assays as a
new modality for single-cell experiments. Instead of measuring the abundance of
molecules—i.e., levels of DNA, RNA, or protein—from single cells and predicting cell
functional states (e.g., cell cycle phase), our key innovation is to directly quantify
enzymatic activities in single cells by measuring the conversion of substrates to products
by single cell extracts in a high-throughput DNA sequencing experiment. Our approach
is compatible with existing platforms that measure gene expression in thousands to
millions of individual cells and enables many different enzymatic activities to be
measured simultaneously.

## Key facts

- **NIH application ID:** 10672993
- **Project number:** 5R01AG071467-04
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Jay R Hesselberth
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $626,680
- **Award type:** 5
- **Project period:** 2020-09-11 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10672993

## Citation

> US National Institutes of Health, RePORTER application 10672993, Biochemistry at single-cell resolution: a new approach to understand functional heterogeneity (5R01AG071467-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10672993. Licensed CC0.

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