BIOshell IgG 1000 Å Diphenyl is a high-speed, high-performance liquid chromatography column based on a new wide-pore (1000 Å) Fused-Core® particle design. The particle provides a thin porous shell of high-purity silica surrounding a solid silica core. This particle design exhibits very high column efficiency due to the shallow diffusion paths in the 0.5 μm thin porous shell and the small overall particle size of 2.7 μm. The densely bonded, extensively endcapped diphenylmethyl bonded phase of BIOshell IgG 1000 Å Diphenyl provides a stable, reversed-phase packing that can be used for separating high molecular weight compounds, such as proteins.