tartrazine

Tartrazine (FD&C Yellow No. 5) is a synthetic azo dye traditionally used as a food coloring agent. In a novel medical application being evaluated by Johns Hopkins University, topical tartrazine is utilized as an optical clearing agent to induce temporary skin transparency. The mechanism involves the dye's strong light-absorption properties, which, when dissolved in the interstitial fluid of tissues, increase the refractive index of the aqueous environment to match that of lipids. This reduction in refractive index mismatch significantly minimizes light scattering, allowing for deeper and clearer optical imaging of subcutaneous structures. This effect is reversible and is being investigated for diagnostic applications in dermatology and medical imaging.

Brand names

FD&C Yellow 5Food Yellow 4Tartran Yellow

Other names

FD&C Yellow No. 5E102E-102E 102Acid Yellow 23C.I. 19140Hydrazine Yellow