The development of micro-DNA arrays has opened tremendous opportunities for measuring gene expressions over repeated experiments. The scope of applicability of micro-arrays goes from medical diagnosis to bio-discovery. In particular micro-array technology is fit to provide insight into gene regulatory mechanisms. This research involves the combination of hardware design using various technologies (e.g., glass or silicon substrates, micro-cantilever, capacitive, optical sensing, ...) as well as software technologies for processing DNA-array data and link them to other diagnostic or ontological information. Moreover, a lab on a chip will combine hardware sensing of DNA, possibly coupled with micro-fluidic circuits for sample delivering and pre-processing, with in situ data processing, possibly enhanced with means for communicating off-chip for data verification and analysis. Labs on a chip will benefit the medical profession, by expanding the ability of diagnosis and reducing the costs, and will be very appealing to semiconductor manufacturers, due to the potential market size.