Photochemical Barcodes.

Area of Science:

• Photochemistry
• Molecular Imaging
• Biotechnology

Background:

• Developing methods for precise labeling of biological samples is crucial for tracking cellular dynamics.
• Existing fluorescence labeling techniques often lack spatial control or can be toxic to living organisms.
• Photoactivatable molecules offer potential for controlled activation and signal generation.

Purpose of the Study:

• To design a photochemical strategy for encoding spatial fluorescence signals in vivo.
• To develop a method for creating distinct, multi-color fluorescence barcodes within individual particles.
• To enable spatiotemporal tracking of biological targets using these unique fluorescence codes.

Main Methods:

• Utilized a photoactivatable borondipyrromethene (BODIPY) molecule.
• Developed a two-step photoinduced disconnection of oxazines flanking the BODIPY.
• Controlled fluorescence signal intensity and ratios by adjusting photon dose for barcoding polymer beads.
• Applied the technique to label living nematodes with distinct barcodes.

Main Results:

• Generated a mixture of three emissive molecules with resolved fluorescence within polymer beads.
• Achieved precise regulation of relative amounts and emission intensities of fluorophores.
• Successfully performed photochemical barcoding of beads in living nematodes using visible wavelengths and mild illumination.
• Demonstrated labeling of different regions within the same animal with distinct barcodes.

Conclusions:

• The photochemical strategy enables the generation of multiple, distinguishable fluorescence barcodes in a single biological sample.
• This method allows for precise spatiotemporal tracking of otherwise indistinguishable targets.
• The technique is non-toxic and suitable for long-term monitoring of biological dynamics in vivo.