Different Matrices of Columns: Bead Resin, Fibro, Membrane Adsorber, and Monolith

Chromatography with columns is widely used for the purification of various biomolecules, including RNA. We will examine the differences between bead resin, fibro, membrane adsorber, and monolith. Table 1 provides a summary of their different attributes, and Figure 1 illustrates the microscopic structure of the column matrices.

	Bead Resin	Fibro	Membrane	Monolith
Pore size	15-40 nm	0.2-2.0 μm	3-5 μm	2 μm
Surface area	~ 40 m2/g	~ 10 m2/g	< 2 m2/g	< 7 m2/g
Mass transfer	Convection and diffusion	Convection	Convection	Convection
Surface chemistry	Affinity, HIC, IEX, SEC, MMC	Affinity	IEX, HIC	Affinity, HEX, IEX, MMC
Target molecule	All types of molecules, but maximum binding with anything similar or smaller than monoclonal antibodies	Shear stress sensitive molecules, and large molecules, like mRNA	Shear stress sensitive molecules, and large molecules, like mRNA	Shear stress sensitive molecules, and large molecules, like mRNA
Mode of operation	Mainly B/E, sometimes FT polishing	B/E for large molecules, polishing all kinds of targets in FT mode	B/E for large molecules, polishing all kinds of targets in FT mode	B/E for large molecules, polishing all kinds of targets in FT mode
Matrix material	Cross-linked agarose or dextran, polymer, silica gel, or other porous materials	Cellulose, or other fibrous materials	Various types of synthetic polymers, such as polyethersulfone (PES), cellulose, porous polyacrylamide hydrogel	Rigid, continuous materials, such as organic polymers (e.g., methacrylate-based)
Process time	Couple of hours	Within an hour, or even minutes	Within an hour, or even minutes	Within an hour, or even minutes
Residence time	2-10 min	Seconds	Seconds	Seconds
Device availability	Pre-packed or pack your own	Plug-and-play device	Plug-and-play device	Plug-and-play device
Rapid cycling	No	Yes	Yes	Yes

Reference:

1. Pictures adopted from Cytiva.