Dansyl chloride is a reactive probe for the derivatization of primary amines, including those on amino acids, peptides, and polyamines, for detection by HPLC. It has also been used for the derivatization of compounds containing phenol groups, such as steroids, for detection by MS/MS. Dansyl chloride is a fluorescent probe for proteins and enzymes. It displays excitation/emission maxima of 340/535 nm, respectively, in acetone.

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.