Chemistry Reference
In-Depth Information
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Figure 17.20
Microchip layouts for derivatization of aminoacids (a) pre-column Adapted from [167]. © 2006
American Chemical Society, (b) post-column approaches. Adapted from [168] with permission from Wiley-VCH
Verlag GmbH & Co. KGaA © 2002.
of amino acids (arginine, isoleucine, alanine, phenylalanine) in connection to a post-column biogeneration of
electroactive hydrogen peroxide [168]. The microchip layout is shown in Figure 17.20(b).
17.3.6
Sample preparation in cell analysis
One specific and exciting challenge is devoted to cell analysis. On the contrary of previous matter, this section
is focused on a specific sample pre-treatment in biological analysis where different filtering, extraction and
pre concentration strategies have been performed creatively on microfluidic devices. An interesting, specific
and detailed review has been recently published [98].
Each analysis or detection scheme may require different sample preparation steps to obtain purified
analytical targets from a variety of starting samples. The sample processing will depend to a large extent on
the initial sample provided as input to the microfluidic device. This is the case of whole cells, where cell
separation may be necessary, followed by cell lysis to release the proteins, nucleic acids or specific analyte
into solution. The microfluidic devices have the advantages of the speed and cost to integrate various
microstructures to achieve typical sample pre-treatment in cell analysis involving cell/particle filtrating and
sorting, cell lysis, sample extraction and purification and so on. In this section, just selected examples of
sample pre-processing steps in biological treatments on microdevices are described in order to show the
potential of microfluidic technology in this field.
Firstly, regarding cell/particle filtrating and sorting, it is strongly necessary to sort, trap or concentrate the
cells or exogenous material (virus) of interest from complex biological sample for obtaining accurate
information in the downstream analytical step. As an example of genomic analysis, the large population of
blood red cells needs to be separated from the nucleated white cells in order to remove the interfering
