MagSi-Proteomics

MagSi-Proteomics are magnetic silica beads coated with C4, C8 or C18 alkyl groups. MagSi-Proteomics beads provide a reversed phase surface chemistry and are an ideal tool for protein and peptide sample concentration, desalting and fractionation, and reducing sample complexity.

The three surfaces of MagSi-Proteomics beads differ in their levels of hydrophobicity, making them well-suited for different applications and types of samples:

• C4 groups - low hydrophobicity; ideal for purification and fractionation of large biomolecules such as proteins
• C8 groups - intermediate hydrophobicity; suitable for capture and purification of peptides and proteins from urine, saliva and CSF for proteomic profiling and biomarker research
• C18 groups - high hydrophobicity; ideal for desalting of peptides or protein tryptic digest prior to mass spectrometry, concentration of peptides, and capture and purification of peptides and proteins from serum and plasma

Peptides and proteins bind to MagSi-Proteomics beads via hydrophobic interactions between the protein/peptide and the hydrophobic surface of the beads. The higher the hydrophobic character of the proteins and peptides, the stronger the binding towards the reversed phase surface. Proteins and peptides are eluted under organic solvent conditions and can therefore be separated according to their relative hydrophobicities. This occurs using stepwise desorption in increasing concentrations of organic solvents.