Macroporous elastic polyacrylamide monolith columns: processing under compression and scale-up

Macroporous gel (MG) monoliths are novel stationary media with a combination of unique properties such as continuous system of interconnected macropores and high elasticity. Due to the large (1–100 μm) and highly interconnected pores, the polyacrylamide (pAAm) MG monolith columns have low backpressure and can be processed at high flow rates. The highly open macroporous structure with elastic pore walls in pAAm MG monoliths allow for processing under compression and construction of scaled MG monolith columns (when the MG monoliths of the same diameter are placed on top of each other, i.e. composed column). High elasticity of pore walls in the pAAm MGs allows for significant uniaxial compression of monoliths without their breaking and losing column efficiency. A novel approach for elution of bound proteins through the compressed MG monoliths is presented. More than 80% of the bound model protein lysozyme was eluted from the compressed iminodiacetate (IDA) pAAm MGs monoliths (50% compression of initial monolith height) with up to double protein concentration in the peak elution fractions compared to elution through non-compressed monolith.