A DfT strategy for MEMS-based DNA sensors is investigated in this paper. Based on a fault-free and defect model developed for a single sensing element and the VHDL-AMS simulation results, it is implied that an oscillation-based interface might be a potential solution for both testing and read out of this DNA sensor array system. A possible physical implementation of the biosensing array is proposed based on some important boundary conditions. Finally, a potential architecture of the read out electronics to implement the strategy for the array is proposed.