Atto 643 Carboxy Selectively Labels Astrocytes with Minimal Oligodendrocyte Cross-Reactivity

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Astrocytes are vital for brain homeostasis and neural circuit function.
• Sulforhodamine 101 (SR101) is a common astrocyte marker but also labels oligodendrocytes.
• Oligodendrocyte labeling by SR101 can complicate astrocyte-specific studies.

Purpose of the Study:

• To identify a novel, highly specific fluorescent dye for astrocyte labeling.
• To evaluate Atto 643 carboxy as a superior alternative to SR101 for astrocyte imaging.
• To enable precise visualization of astrocyte morphology and distribution in vivo and in brain slices.

Main Methods:

• Screening of far-red fluorescent dyes for astrocyte specificity.
• Comparative analysis of Atto 643 carboxy and SR101 labeling in brain tissue.
• In vivo and acute brain slice imaging of astrocyte morphology and distribution.

Main Results:

• Atto 643 carboxy demonstrated high specificity for astrocytes with minimal oligodendrocyte labeling.
• Unlike SR101, Atto 643 carboxy showed minimal nonspecific uptake in myelin sheaths and neurons.
• Robust imaging of astrocyte morphology and distribution was achieved using Atto 643 carboxy in vivo and in acute slices.

Conclusions:

• Atto 643 carboxy is a highly specific small-molecule probe for astrocyte-selective imaging.
• This dye provides a powerful tool for studying astrocyte structure, dynamics, and function in intact brain tissue.
• Atto 643 carboxy overcomes limitations of SR101, enabling more accurate astrocyte research.