The present invention describes a novel nucleic acid sequencing reagent which consists of a capture moiety, a spacer region and a sequence specific hybridizing region of 4-8 bases. The nucleic acid sequencing reagent of the present invention can also contain an attachment moiety. The nucleic acid sequencing reagent can be arranged into a nested array. This array configuration can then be used to sequence a given template without prior knowledge (de novo) of the wild type or expected sequence in conjunction with primer extension in the presence of a labeled chain terminating nucleotide.