Microfluidics in biotechnology

Abstract

Microfluidics enables biotechnological processes to proceed on a scale (microns) at which physical processes such as osmotic movement, electrophoretic-motility and surface interactions become enhanced. At the microscale sample volumes and assay times are reduced, and procedural costs are lowered. The versatility of microfluidic devices allows interfacing with current methods and technologies. Microfluidics has been applied to DNA analysis methods and shown to accelerate DNA microarray assay hybridisation times. The linking of microfluidics to protein analysis techologies, e.g. mass spectrometry, enables picomole amounts of peptide to be analysed within a controlled micro-environment. The flexibility of microfluidics will facilitate its exploitation in assay development across multiple biotechnological disciplines.

Figure 1

Capillary flow direct PCR analysis. Whole blood samples are used for direct PCR analysis. Samples are manipulated within microfluidic channels.

Figure 2

Microfluidic mass spectrometric protein analysis. Proteins are applied directly to a membrane, desalted and directed by microfluidic channel to mass spectrometric analysis.

Figure 3

Combinatorial peptidomics. Sample solubilisation and protein purification are not necessary, since proteolyric digection may be carried on native cells/tissues (dashed lines). The amino acid filtering (depletion) step may be repeated using combinations of up to 6 amino acid "filters", i.e. chemically reactive surfaces (e.g. derivatised beads) able to covalently cross-link particular amino-acids. Chemical depletion reduces the complexity of the peptide pool to a sufficient degree to make it compatible with direct MS detection.