Abstract

Microfluidics has emerged as a relatively new scientific field enabling fast reaction times and low demands for reactants. Pursuing these advantages, a compartmented, microfluidic reactor was developed in our group which is suitable for the semi-automated processing of complex reaction cascades including solid phases. As one of the first application examples, we analyzed the influence of different reaction paths on the modification of a model protein in a solid-phase reaction. Extensive characterization experiments were performed: Amongst others, an organic phase was identified which is immiscible with water and compatible with the designated PEGylation reactions. Such organic solvents function as separation plugs for different water based reaction plugs within the microfluidic system. Mixing within the microfluidic system was investigated, in order to ensure an efficient solid-phase reaction. Subsequently, solid-phase PEGylation of the target protein was performed within the microfluidic system via two different reaction cascades. The longest reaction cascades comprised all reactions from particle activation, via protein immobilization and PEGylation to elution and consisted of seven steps. PEGylation in the reactor took place with comparable yields and results as in the control reaction outside the reactor. Due to the modularity, the presented reactor proves to be a versatile instrument for semi-automated reactions and parameter screening, being compatible with biological systems. It combines the advantages of closed channel systems like lab on a chip microfluidics with the flexibility and preparative scale sample volume of larger liquid handling stations.

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