DR probe

The DR probe (5-20 μM; 90 min-3.5 h) exhibits a 56-fold fluorescence turn-on effect at 588 nm only when sequentially activated by H₂O₂ and TYR under physiological conditions, with a limit of detection of 28.1 nM for the H₂O₂-mediated activation process^[1].
DR probe (0-30 μM; 1-24 h) shows no cytotoxicity to HSF, PIG1 and A375 cells even at the maximum tested concentration of 30 μM, and it can selectively produce strong fluorescence in A375 melanoma cells (8-fold higher than that in normal PIG1 melanocytes) by responding to endogenous H₂O₂ and TYR^[1].
Guidelines (The following is our recommended protocol, which serves only as a guide and should be modified according to your specific needs).
Cell Fluorescence Imaging:
1.\tCell Preparation: Seed human malignant melanoma cells (A375), normal melanocytes (PIG1) or skin fibroblasts (HSF) into confocal culture dishes, and culture them routinely.
(Optional Control Group): Pre-treat cells with Kojic acid (HY-W050154) (200 μM, a TYR inhibitor) or NAC (HY-B0215) (200 μM, an H₂O₂ scavenger) for 1 hour.
2.\tProbe Incubation:
Aspirate the culture medium, and add serum-free medium or PBS containing 10 μM DR (or SR as a control).
Incubate the cells at 37°C in a 5% CO₂ atmosphere for 3.5 hours.
3.\tWashing: Aspirate the probe solution, and wash the cells 3 times with PBS to remove unbound probes.
4.\tMicroscopic Imaging:
Use a laser confocal scanning microscope.
Excitation (Ex) = 561 nm
Emission (Em) = 570-700 nm (to detect the near-infrared fluorescence of released Resorufin).
Expected Results: A375 cells show strong red fluorescence; PIG1/HSF cells and the inhibitor/NAC treatment groups exhibit extremely low fluorescence.

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