Abstract : We have fabricated a microlaboratory to study diffusion and its coupling with a chemical
reaction. It is composed by an analysis chamber in which electric fields in two
dimensions can be applied to yield stationary and non-stationary concentration profiles.
The spatial simplicity of the electrophoretic flux used allows to systematically analyze
data in the Fourier space. This treatment yields diffusion coefficients of a pure analyte
and thermodynamic and kinetic constants of a reacting mixture. In the scope of developing
separation techniques based on kinetics, we have studied the hybridization reaction
between DNA oligonucleotides with a wide range of kinetic constants. These studies
made us to develop, in collaboration with the Museum National d'Histoire Naturelle, a
quadruplex-based molecular beacon that allows a kinetic discrimination when it hybridizes
to a matched or a mismatched sequence.