The present invention relates especially to a process for the localized distribution of drops of a liquid of interest on an active surface. The process comprises the following steps: an introduction of liquid of interest into a box containing the said active surface, and an extraction of liquid of interest from the said box, the said active surface and also the other surfaces inside the box being substantially non-wetting with respect to the liquid of interest, with the exception of several uptake areas localized on the said active surface, which are each suitable for taking up a drop of liquid of interest. The uptake areas may surround working areas. The present invention also relates to processes for the electrochemical and optical detection of at least one analyte in a liquid of interest, and to an electropolymerization process.