# Near-infrared fluorescent probes and optogenetic tools

> **NIH NIH R35** · ALBERT EINSTEIN COLLEGE OF MEDICINE · 2024 · $522,480

## Abstract

ABSTRACT
High optical transparency, low light-scattering and low autofluorescence of mammalian tissues in the near-
infrared spectral range open up the possibility for non-invasive imaging, sensing and light-regulation of cellular
biochemistry, tissue metabolism and physiology in mammals. Due to near-infrared absorption and the use of
heme-derived biliverdin produced in all mammalian tissues as a chromophore, bacterial phytochromes are
currently the preferred molecular templates for the development of genetically encoded optical reagents for in
vivo applications. Here we propose a variety of near-infrared imaging probes and optogenetic tools. We will
focus on the development of fluorescent proteins with higher brightness, greater bathochromic shift and
exhibiting photoconversion, as well as on the search for new natural near-infrared absorbing proteins as initial
templates. These probes should lead to deeper and spatiotemporally precise in vivo imaging. We will also
focus on the visualization and manipulation of endogenous molecules in cells and whole organisms using
antigen-stabilized fusions of near-infrared fluorescent proteins with genetically encoded nanobodies. This will
allow background-free detection of various intracellular antigens and antigen-dependent regulation of protein
and cellular functions. In addition, we will develop near-infrared optogenetic modules with improved
performance in mammalian cells and use them to engineer light-controlled enzymes, receptors and cells. This
should open up possibilities for user-defined regulation of cellular and organismal functions in vivo. All
proposed near-infrared probes will spectrally complement existing reagents in the visible range. Planned
studies will also expand our basic knowledge of photochemistry and light-induced signaling of phytochrome
photoreceptors. Novel genetically encoded fluorescent probes and optogenetic tools will drive the development
of more sensitive in vivo imaging and light-control technologies, optimization of gene delivery strategies,
development of targeted non-invasive illumination, and refinement of optical readouts in tissues and animals.

## Key facts

- **NIH application ID:** 10798127
- **Project number:** 5R35GM122567-08
- **Recipient organization:** ALBERT EINSTEIN COLLEGE OF MEDICINE
- **Principal Investigator:** Vladislav Verkhusha
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $522,480
- **Award type:** 5
- **Project period:** 2017-05-01 → 2028-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10798127

## Citation

> US National Institutes of Health, RePORTER application 10798127, Near-infrared fluorescent probes and optogenetic tools (5R35GM122567-08). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10798127. Licensed CC0.

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