The DOSY experiment (Diffusion Ordered SpectroscopY) is the measure of diffusion coefficients by NMR. It has been developped in order to facilitate the complexe mixture analysis without physical separation.
Data acquisition and processing required dedicated NMR devices and softwares (NMRnotebook, DOSY Module).

This experiment will monitor any modification of the solvent or of the solutes, and molecular events such as molecular interactions or associations. It can also be used for the separation of molecules present in a mixture, separation based on their different diffusion properties.

There are many different applications:

• Trace detection and quantification
  Application note available: Using DOSY for complexe mixture analysis

• Protein / ligand interaction screening (ligands fixed, even partially, to the target protein will see their diffusion coefficient modified). This technique can be applied successfully on ligand libraries.
  Application note available: Using DOSY for sample fingerprinting

• Molecular-mass and branching analysis of polymers
  

• Polluant or additive detection (polymers in liquides)
  

• Monomer / dimer equilibirum determination
  In-tube NMR "chromatography"
  

• Determination of Critical Micellar Concentration