Shim-pack Scepter C4-300 has very large pores of 30 nm and is therefore optimally suited for biological samples such as proteins and monoclonal antibodies. Proteins can be analysed with this C4 phase up to a molecular weight of 150,000 Daltons. Especially for the analysis of antibodies, the column is stable even under acidic conditions as well as high temperatures. In addition to these advantages, the C4 phase more effectively separates very hydrophobic substances that are difficult to separate with the regular C18 column.