# Time-Resolved Confocal Fluorescence Microscope with Single Molecule Sensitivity

> **NIH NIH S10** · TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR · 2022 · $600,000

## Abstract

PROJECT SUMMARY
 This application seeks funds to purchase a time-resolved confocal fluorescence microscope with single
molecule sensitivity. This instrument will support NIH-funded users in three departments and three colleges
within the Texas A&M University community and will provide numerous single molecule fluorescence (SMF)
capabilities currently unavailable to a dozen laboratories via a new shared user facility. The requested five-line
pulsed laser system will enable numerous multi-color correlation, fluorescence lifetime, and polarization
applications through its time-correlated single photon counting (TCSPC) capabilities that are required by the user
group. The most common application will be fluorescence resonance energy transfer (FRET) measurements
used to determine intra- and inter-molecular distance information in a wide-range of macromolecular complexes.
While ensemble FRET measurements are often compromised by various artifacts and limitations, the single
molecule FRET (smFRET) capabilities of the requested microscope system substantially improve the accuracy
of such measurements and provide unique ways to quantify molecular dynamics. An additional key application
of the proposed instrument will be the development of a novel approach for measuring rotational mobility termed
single molecule rotational diffusion microscopy on the microsecond timescale (µs-SiMRoD). Rotational mobility
is an underutilized experimental read-out useful for probing the effects of macromolecular crowding, or other
similar situations where the molecular assembly influences probe mobility. SiMRoD has no corresponding
ensemble analog, emphasizing the importance of the instrument’s single molecule sensitivity. Though the
majority of users will examine well-controlled in vitro systems, in cellulo FRET imaging will benefit from the
fluorescence lifetime microscopy (FLIM) capability of the system, which will generate more accurate
measurements (FLIM-FRET) than are available from a typical confocal microscope. The Major Users will
examine fundamental and diverse cell biological and mechanistic biochemistry questions focused on
phosphoinositide binding proteins, nucleosomes, molecular chaperones, membrane fission, nuclear pores, and
mitochondrial integrity. All the colleges and departments represented in the user group will contribute to
instrumentation costs, emphasizing the fundamental importance of the new microscope capabilities in the growth
of current research programs. The instrument will be housed in the College of Medicine by the Department of
Molecular and Cellular Medicine, which has donated substantial equipment and space for the microscope facility.
Altogether, the identified users have planned new research directions that will require over 93% of the total
accessible user time, indicating the substantial demand for both existing and new projects. In total, the requested
time-resolved confocal fluorescence microscope with single molecule sensitivity will...

## Key facts

- **NIH application ID:** 10415601
- **Project number:** 1S10OD032208-01
- **Recipient organization:** TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
- **Principal Investigator:** SIEGFRIED M MUSSER
- **Activity code:** S10 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $600,000
- **Award type:** 1
- **Project period:** 2022-09-01 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10415601

## Citation

> US National Institutes of Health, RePORTER application 10415601, Time-Resolved Confocal Fluorescence Microscope with Single Molecule Sensitivity (1S10OD032208-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10415601. Licensed CC0.

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