Electrokinetics for sample preparation of biological molecules in biological samples using microfluidic systems

Sample preparation is the first part of every analytical method, but is often considered only after
optimization of the method. It is traditionally performed using a range of highly manual techniques,
with solid-phase extraction, liquid-liquid extraction, protein precipitation, ultracentrfiguation, etc,
being used depending on the targets and the application. Here, we will focus on alternatives based on
electrokinetics for applications including sample clean up, concentration and derivatisation of large
biological molecules (DNA, peptides, and proteins) of diagnostic importance, as well as small
molecules as a tool for therapeutic drug monitoring. The review describes these approaches in terms of
mechanism, applicability and potential to be integrated into a lab on a chip device for directly
processing biological samples.