DNA sequencing with reagent recycling on wiregrid

The present invention relates to DNA sequencing with reagent cycling on the wiregrid. The sequencing approach suggested with which allows to use a single fluid with no washing steps. Based on strong optical confinement and of excitation light and of cleavage light, the sequencing reaction can be read-out without washing the surface. Stepwise sequencing is achieved by using nucleotides with optically cleavable blocking moietys. After read-out the built in nucleotide is deblocked by cleavage light through the same substrate. This ensures that only bound nucleotides will be unblocked.