The USI is a multi-part key separated by colon characters; for example, mzspec:PXD006512:CNHPP_HCC_LC_profiling_L006_P_F1:scan:64442:VADALTNAVAHVDDMPNALSALSDLHAHK/3. This USI consists of five basic components, which indicates that the peptide VADALTNAVAHVDDMPNALSALSDLHAHK with a charge of 3 is identified in the raw file (CNHPP_HCC_LC_profiling_L006_P_F1.raw of PXD006512 dataset), with the scan number, 64442.

For more information, including the draft specification, please see http://psidev.info/usi/

Identifier examples