2,2'-Dipyridyldisulfide

2,2′-Dipyridyldisulfide, sometimes known as DPS, is used for preparing thiols and activating carboxylic acid for coupling reactions, as in the following reaction:
 * [[Image:2,2'-Dipyridyldisulfide Reaction.svg|600px]]

Uses
It is also used in molecular biology as an oxidising agent, for example to oxidise free thiols to form disulfide bonds in proteins.