Rhodamine B-Dextran chloride (MW 500000)

Operating Instructions (The following is a recommended experimental protocol for guidance only; please adjust it according to your specific needs).
1. Stock Solution Preparation
1.1 Solvent: Most dyes are typically dissolved in organic solvents, such as anhydrous DMSO.
1.2 Concentration Recommendation: It is generally recommended to prepare a high-concentration stock solution at 1-10 mM.
2. Working Solution Preparation
2.1 Diluent: Serum-free medium or PBS is usually used. Proteins and esterases in serum may interfere with staining results or cause dye hydrolysis.
2.2 Precautions: Adjust the working solution concentration as needed; prepare and use it immediately.
3. Staining Procedure
3.1 Sample Type: Ex vivo human full-thickness skin and dermis prepared with a dermatome^[1].
3.2 Incubation Conditions: Apply the dye-loaded Nanopatch to the skin surface and leave it in place for 2 minutes.
4. Detection and Analysis
4.1 Instrument: Multiphoton fluorescence microscope.
4.1.1 Excitation wavelength: 760 nm; a 550-670 nm bandpass filter is used to detect the emission wavelength.
4.2 Result Analysis:
4.2.1 Fluorescence intensity change: As the dye diffuses and is cleared from the skin layers, the fluorescence intensity (which is proportional to the dye concentration) decreases over time.
4.2.2 Fluorescence localization: The dye diffuses laterally from the Nanopatch puncture sites, passing through the stratum corneum, viable epidermis, dermoepidermal junction, and dermis.
4.2.3 Color change: Red fluorescence (displayed as pseudocolor in images) corresponds to the dye signal.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.