Silicon-based microcantilevers for multiple biological sample deposition

Arrays of silicon-based microcantilevers with passivated aluminum electrodes properly designed have been used to generate microarrays by depositing microspots of biological samples using a direct contact deposition technique. Using this approach, with a single loading, arrays of more than a hundred spots, from the femtoliter to the picoliter range, containing fluorescent-labelled oligonucleotides (15 mers) and proteins were directly patterned on a glass slide. The aim here was to check whether our system could be used for depositing various biological samples with the same cantilevers without the need to replace them for each sample. The strategy was to adapt the conventional cleaning and drying procedures used with a commercial DNA or protein microspotter. All the results presented demonstrate that our system perfectly matches the need for generating high-density DNA and protein chips in terms of size, density and the capacity of depositing different samples without cross-contamination.