FM-red

• CAT Number: I044999
• Molecular Formula: C41H46ClN5O9
• Molecular Weight: 788.29
• Purity: ≥95%
• Synonyms: [2-[4-(dimethylamino)phenyl]-4-[2-[4-[4-(2,5-dioxopyrrol-1-yl)butanoylamino]piperidine-1-carbonyl]phenyl]chromen-7-ylidene]-diethylazanium;perchlorate
• InChI: InChI=1S/C41H45N5O5.ClHO4/c1-5-44(6-2)31-17-18-33-35(27-36(51-37(33)26-31)28-13-15-30(16-14-28)43(3)4)32-10-7-8-11-34(32)41(50)45-24-21-29(22-25-45)42-38(47)12-9-23-46-39(48)19-20-40(46)49;2-1(3,4)5/h7-8,10-11,13-20,26-27,29H,5-6,9,12,21-25H2,1-4H3;(H,2,3,4,5)
• InChIKey: AYCLQMGPYXYAKZ-UHFFFAOYSA-N
• SMILES: CC[N+](=C1C=CC2=C(C=C(OC2=C1)C3=CC=C(C=C3)N(C)C)C4=CC=CC=C4C(=O)N5CCC(CC5)NC(=O)CCCN6C(=O)C=CC6=O)CC.[O-]Cl(=O)(=O)=O

FM-red (Cat No.:I044999) is a red‑emitting, environment‑sensitive fluorescent probe designed for selective detection and labeling of protein‑thiol (–SH) groups in live cells and in vivo systems. It exhibits long–wavelength emission (~655 nm) and responds rapidly (within ~10 minutes) upon binding to protein thiols, making it ideal for imaging cellular sulfhydryl dynamics and assessing redox status. FM‑red has low cytotoxicity (e.g. ≤ 20 µM over 48 h in HeLa cells), is soluble in DMSO, and has been used to monitor thioredoxin (Trx) redox state changes.