Microfabricated Sample Extraction and Concentration

BioMEMS can miniaturize sample preparation so that small quantities of biological material are extracted and concentrated before analysis.

Techniques

1. Microfiltration: Membranes or microfabricated pores retain cells, particles or macromolecules according to size.
2. Microfluidic trapping: Structures such as pillars, wells or chambers physically capture target particles or cells.
3. Centrifugal/inertial concentration: Controlled fluid motion drives particles toward selected regions of a microchannel.
4. Dielectrophoretic concentration: Non-uniform electric fields attract or repel polarizable cells and particles, concentrating them at electrode regions.
5. Magnetic concentration: Magnetic beads bound to target molecules/cells are captured with magnetic fields.
6. Electrophoretic methods: Electric fields transport charged molecules and can concentrate or separate them.
7. Membrane-based extraction: Selective membranes can isolate target molecules or components from complex samples.

Importance

These techniques reduce sample volume, shorten preparation time and facilitate integration with downstream sensing and analysis on a Lab-on-Chip.