The present invention is to a prefilter for purification systems such as affinity chromatography columns and ultrafiltration systems. The prefilter, positioned upstream of the system inlet, reduces the presence of non-specific binding (NSB) species that enter the system, thereby extending the yield, capacity and lifetime of the system. Suitable agents include but are not limited to hydrophobic entities; lipophilic entities; activated carbon; charged cation or anion entities; ligands; particles such as fumed silica, glass, controlled pore glass or derivitized version of each; silica or silicates; and combinations thereof. The material(s) can be incorporated into a variety of media such as fibers, beads, membranes and the like and then incorporated into a variety of device designs including lenticular pads, depth filters, bead containing columns, spiral wound devices, TFF devices and the like.