Tartrazine-enabled enhanced image depth penetration with quantitative oblique back-illumination microscopy

Area of Science:

• Biomedical Optics
• Optical Imaging
• Tissue Optics

Background:

• Light scattering limits optical imaging in thick biological tissues.
• Water-soluble dyes like tartrazine can induce reversible optical transparency via refractive index matching.
• Enhanced imaging depth is crucial for various biomedical applications.

Purpose of the Study:

• To evaluate the efficacy of topical tartrazine-agarose in improving imaging depth.
• To assess the impact of tartrazine on quantitative oblique back-illumination microscopy (qOBM) in mouse skin.
• To determine the reversibility of tartrazine's effect on imaging depth.

Main Methods:

• Topical application of tartrazine-agarose solution to mouse abdominal skin.
• Utilizing quantitative oblique back-illumination microscopy (qOBM) for 3D label-free imaging.
• Employing an entropy cutoff metric to quantify imaging penetration depth.
• Assessing imaging depth before, during, and after dye application.

Main Results:

• Tartrazine application significantly improved imaging depth by a factor of 1.5-2x.
• The improvement in imaging depth was wavelength-dependent.
• No residual effect on imaging depth was observed after dye removal, indicating reversibility.

Conclusions:

• Topical tartrazine effectively enhances optical transparency and imaging depth in mouse skin.
• qOBM combined with tartrazine shows promise for label-free 3D imaging.
• These findings support the translation of tartrazine-based optical clearing techniques into clinical settings for dermatology, gynecology, and surgical oncology.