# Development of the first label-free and high-throughput, cell-based assay that reports on specific enzyme activities

> **NIH NIH R44** · SAMDI TECH, INC. · 2020 · $1,076,401

## Abstract

Project Summary / Abstract
Cell-based assays that quantitate the effect of small molecules on cellular behavior are powerful tools in
cancer research. The ability to assess small molecules in a physiologically relevant environment is informative,
as the assays simultaneously evaluate compound permeability, toxicity, and potency. To date, cell-based
assays are largely limited to measure global changes such as phenotype, proliferation, or gene expression.
The current challenge is to develop cell-based assays for specific enzyme activities to augment and
accelerate drug discovery campaigns. Notably, the most common strategies for measuring enzyme
activities, such as radioactivity, absorbance, and fluorescent labels, often cannot be delivered to the
appropriate target within the cellular environment and they are susceptible to high rates of false positives. This
proposal describes the continued development and validation of a novel label-free methodology that combines
cell culture and lysis on customized surface chemistries to allow a mass spectrometry readout for distinct
enzyme activities. The approach uses functionalized self-assembled monolayers (SAMs) that present cell
adhesion ligands along with substrates for the relevant cellular enzyme targets. Cells are cultured on the
monolayers in the presence of small molecules, and then lysed such that enzymes within the lysate have
immediate access to convert the immobilized substrate to a product. An advantage of using SAMs on gold is
their compatibility with matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS), an
approach termed “SAMDI”, that records the activity of specific enzymes within the lysate. This technique,
termed Tandem Culture and Lysis (TCAL)-SAMDI, offers a novel, powerful tool for a quantitative readout of
virtually any cellular enzyme activity and represents new capabilities for high-throughput and label-free, cell-
based screens for drug discovery.

## Key facts

- **NIH application ID:** 10076910
- **Project number:** 9R44CA243990-02A1
- **Recipient organization:** SAMDI TECH, INC.
- **Principal Investigator:** Zachary Gurard-Levin
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $1,076,401
- **Award type:** 9
- **Project period:** 2020-07-10 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10076910

## Citation

> US National Institutes of Health, RePORTER application 10076910, Development of the first label-free and high-throughput, cell-based assay that reports on specific enzyme activities (9R44CA243990-02A1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10076910. Licensed CC0.

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