In vivo tissue clearing with tartrazine and other dye molecules

Tartrazine, along with many other absorbing molecules, has recently emerged as a promising tissue-clearing agent for achieving transient and reversible optical transparency in live animals. In this mini-review, we describe the fundamental physical origins of tissue opacity, extract engineering principles guiding the design of next-generation dye-based clearing agents, and summarize recent advances in dye-enabled in vivo tissue clearing. We also discuss current challenges and offer forward-looking perspectives to inform future research.