Ubiquitin is a kind of small protein widely existed in eukaryotic cells, the size of 76 amino acid residues. Ubiquitin can interconnect with each other through enzymatic reaction, and then mediate the degradation of target protein. Its main function is to label proteins that need to be broken down for degradation by the 26S proteasome. Some receptors on the regulatory subunit on the 26S proteasome can recognize the polyubiquitination protein linked to K48 and K11, and the 20S core subunit hydrolyzes the substrate under the energy of ATPase. At KS-V, the synthesis of each peptide requires a strict quality control process. The unique comprehensive quality control management platform requires three reverse high performance liquid chromatography (RP-HPLC) and mass spectrometry (MS) for each peptide in the synthesis, purification and QC process to ensure the quality of each peptide. Additional QA rechecks are required to further ensure high quality peptide delivery.