Optical clearing works by altering the refractive index of tissues to match that of the surrounding medium. This is typically achieved through the use of clearing agents, which can be categorized into several types:
1. Aqueous-based: These agents, such as glycerol and FocusClear, are water-soluble and often used for short-term clearing. 2. Organic Solvent-based: Agents like benzyl alcohol and benzyl benzoate (BABB) or tetrahydrofuran (THF) are effective for long-term clearing but can be harsh on tissues. 3. Hyperhydrating: Solutions such as Scale and SeeDB increase the hydration of tissues, making them more transparent. 4. Hydrophilic Refractive Index Matching: Agents like CLARITY and CUBIC use hydrophilic chemicals to match the refractive index of tissues.
