Protein/Peptide Purification
Desalting/Concentration
Mass Spectrometry requires volatile buffer to be used. When the sample is not in a suitable buffer or the provided solution is too diluted, a desalting or centration step is used. Two techniques of desalting/concentration are available in our facility. The technique will be chosen depending on several parameters (volume of sample, composition of solution, etc.)
Zip-Tip C4 or C18
Zip-Tip is a tip containing C4 or C18 phase packed in the end of the tip. It allows desalting and concentrating samples that are in aqueous buffer. C18 Zip-Tips are used for peptides and small proteins whereas C4 Zip-Tips are used for higher mass proteins.
Amicon Ultra-0.5mL (cut-off 3 kDa)
Amicon Ultra-0.5mL are filtration devices with dialysis vertical membrane that allows reducing the volume and performing buffer exchange with spin times lower than 2.5 hours. It allows desalting and concentrating samples that are in aqueous and organic buffer up to 500 µL (volume up to 4 mL can also be desalted using the same technique).
Precipitation
Proteins are precipitated using 2D-clean up kit (GE Healthcare) to remove detergents, chaotrops, salts, lipids,…
