AF 488 maleimide 

AF 488 maleimide is a thiol-reactive dye used to label SH groups of proteins, which can attach the AF 488 fluorophore to cysteine residue-containing proteins and peptides as well as other thiolated molecules. AF 488 maleimide enables real-time visualization of dynamic pilus extension and retraction in live bacterial cells via epifluorescence microscopy (Ex/Em = 470/520 nm)^[1].

AF 488 maleimide (25 μg/mL; 5-30 min) brightly labels type IVa competence pili in Vibrio cholerae PilA_S67C cells, enabling real-time visualization of dynamic pilus extension and retraction via epifluorescence microscopy^[1].
AF 488 maleimide (25 μg/mL) brightly labels type IVa MSHA pili in Vibrio cholerae MshA_S156C and MshA_T81C cells, enabling visualization via single-time-point epifluorescence microscopy^[1].
AF 488 maleimide (25 μg/mL) brightly labels type IVb TCP pili in Vibrio cholerae TcpA_T184C cells, enabling visualization via single-time-point epifluorescence microscopy^[1].
AF 488 maleimide (25 μg/mL; 5-30 min) brightly labels type IVc Tad pili in Caulobacter crescentus PilA_T36C cells, enabling real-time visualization of dynamic pilus activity, and when used alongside pre-treatment with PEG5000-mal, allows visualization of static, retraction-blocked pili via epifluorescence microscopy^[1].

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

734.69

C₃₁H₂₇N₄NaO₁₂S₂

Solid

Orange to red

NC(C=C1)=C(S(=O)(O[Na])=O)C2=C1C(C3=C(C(O)=O)C=C(C(NCCCCCCN4C(C=CC4=O)=O)=O)C=C3)=C(C=C5)C(O2)=C(S(=O)([O-])=O)C5=[NH2+]

Room temperature in continental US; may vary elsewhere.

-20°C, protect from light, stored under nitrogen

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Ellison CK, et al. Real-time microscopy and physical perturbation of bacterial pili using maleimide-conjugated molecules. Nat Protoc. 2019;14(6):1803-1819.  [Content Brief]