Hamilton chromatography resins can be ordered in bulk, i.e. not packed into column hardware. This is a low cost approach to application-specific testing and analyses. Bulk resin can also be purchased to pack your own columns. Guard columns can provide many benefits when used upstream from an analytical, preparative, or semi-preparative column. Guard columns are typically chosen to have the same packing as the primary column. Any compounds or particulate material that would block the frits or highly adsorb to the primary column will do so on the guard column, thereby protecting and extending the lifetime of the more costly column. In addition to protective uses, guard columns can be used as sacrificial preparative components. PRP-X600 is a superficially porous support. Superficial porosity results in fast separation with better sample capacity and shortened diffusion path, resulting in sharper sample bands than nonporous supports. Rapid gradient changes typically lower column efficiency, however, PRP-X600 shows very favorable biomolecule separation efficiency with much shorter run times when rapid gradient changes are employed.