Protamine sulfate salt, derived from herring, is primarily used in medicine as an antidote for heparin overdose. It works by binding to heparin, neutralizing its anticoagulant effects, and restoring normal blood clotting. This application is critical in surgical settings or after procedures where heparin is used to prevent blood clots. Additionally, it is employed in certain drug delivery systems to stabilize and control the release of therapeutic proteins. Its ability to interact with nucleic acids also makes it useful in biotechnology for DNA and RNA extraction processes.