Tartrazine for Optical Clearing of Tissues: Stability and Diffusion Issues.

Area of Science:

• Biomedical Engineering
• Optical Physics
• Materials Science

Background:

• Tartrazine (TZ) is a yellow food dye used in research.
• Tissue optical clearing enhances imaging by reducing light scattering.
• Accurate preparation of TZ solutions is crucial for reproducible optical clearing.

Purpose of the Study:

• To develop a fast protocol for preparing aqueous tartrazine solutions of desired concentrations.
• To investigate the stability of TZ solutions at various concentrations.
• To quantify the diffusion of TZ in ex vivo skeletal muscle for optical clearing.

Main Methods:

• Density measurement of tartrazine powder to determine solution concentrations.
• Stability testing of TZ solutions at different concentrations.
• Immersion of ex vivo skeletal muscle samples in TZ solutions.
• Measurement of tissue transparency and TZ diffusion time.

Main Results:

• A protocol for rapid preparation of TZ solutions was established.
• TZ solution stability decreases exponentially with increasing concentration.
• Ex vivo skeletal muscle transparency increased exponentially upon immersion in 40% TZ solution.
• The diffusion time of TZ in 0.5 mm thick skeletal muscle was determined as 5.39 ± 0.49 min.

Conclusions:

• The developed protocol allows for fast and accurate preparation of TZ solutions for tissue optical clearing.
• Understanding TZ solution stability is critical for experimental design.
• The quantitative data on TZ diffusion aids in optimizing optical clearing protocols for skeletal muscle.