# New Class of Bright, Sharp, Tunable Near-Infrared Fluorophores for Flow Cytometry

> **NIH NIH R44** · NIRVANA SCIENCES, INC. · 2020 · $997,404

## Abstract

Abstract
Polychromatic flow cytometry (FC) is one of the most powerful analytical techniques routinely used by both basic
research and clinical diagnostics laboratories for the immunological categorization of cells. Dyes used for FC
typically exhibit broad fluorescent emission bands with full-width-at-half-maximum (fwhm) values of 50–80 nm.
This limits the maximum number of dyes, and thus the number of cell biomarkers, that can be resolved in a given
experiment. Compensating for spectral overlap between dyes is currently viewed as a necessary part of
experimental design, requiring extensive pre-assay experimentation and mathematical compensation, thereby
introducing experimental error and reducing sensitivity. Bacteriochlorins are a unique class of fluorescent dyes
that offer a solution for accurate multiplexing with minimal compensation due to their very narrow emission bands
(fwhm of 25-35 nm), typically less than half the spectral width of existing dyes. Through chemical modification,
they can be tuned to emission wavelengths from the far red through the near-infrared (NIR) spectrum (700–900
nm). In addition, bacteriochlorins share a common excitation band, making possible the development of a full
spectrum of NIR dyes excited by a single UV light source. To render bacteriochlorin dyes commercially viable,
Phase 2B efforts will be focused on: 1) improving and expanding the bacteriochlorin dye portfolio and synthesis
methods; 2) validating dye performance in FC panels with NIRvana Sciences’ collaborators, and 3) developing
procedures, methods, and protocols for commercial scale manufacturing. This Phase 2B SBIR proposal is
intended to continue the refinement and transfer of bacteriochlorin technology for commercial development,
resulting in a bacteriochlorin dye portfolio with high impact potential for polychromatic FC. This enhanced
multiplex capability will advance not only basic immunology research, but it will also accelerate novel vaccine
and adjuvant discovery for HIV, malaria, tuberculosis, and emerging infectious disease threats. Greater
multiplexing also is critical for analyzing reduced volume samples, for single cell studies, and for high throughput,
high resolution analyses.

## Key facts

- **NIH application ID:** 9900733
- **Project number:** 5R44AI112302-05
- **Recipient organization:** NIRVANA SCIENCES, INC.
- **Principal Investigator:** Christopher J MacNevin
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $997,404
- **Award type:** 5
- **Project period:** 2014-06-15 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9900733

## Citation

> US National Institutes of Health, RePORTER application 9900733, New Class of Bright, Sharp, Tunable Near-Infrared Fluorophores for Flow Cytometry (5R44AI112302-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9900733. Licensed CC0.

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