Shim-pack Scepter prep columns consist of an organosilane hybrid particle for excellent stability and performance and reliable scaleup up from a Scepter C18-300 analytical column. The C18-300 phase has a larger pore size than Scepter C18-120 and is less retentive, which reduces analysis time and is more reproducible for the analysis of compounds that are strongly retained on typical C18 columns. It is recommended for mid- to large-sized molecules (above 5000 MW) to ensure retention and avoid size exclusion effects. It is ideal for LC and LCMS analysis of peptides, proteins, intact monoclonal antibodies and their subunits up to 150 kDa, and is compatible with 100% aqueous mobile phase conditions. USP L1, pore size: 300A, pH range: 1-12, max pressure: 45 MPa/4500 bar/6,500 psi, fully endcapped. Method development on an analytical Scepter C18-300 column is highly recommended before purchasing a prep column. Prep columns cannot be returned or exchanged once used. Use with prep guard cartridges 227-31207-03 and holder 227-31171-03 to prolong the life of the column. Similar to XBridge Protein BEH C18.