BDP 581/591 maleimide is a thiol reactive dye for the labeling of sulfhydryl groups of proteins and peptides. The dye is useful for a variety of applications, such as microscopy, fluorescence polarization experiments, and even ROS detection (upon reaction with ROS, the dye changes its fluorescence).

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.