AbstractIn this paper we propose a universal rewriting system whose computational steps closely resemble the manner in which nature computes double stranded DNA molecules. The basic data structure is given by a couple of strings paired by a complementarity relation (such as the Watson–Crick one), and the rewriting rules have a biotechnological implementation as DNA computing standard procedures. The antiparallel orientation of the formal strings laying on the double structure is taken into consideration, as in [G. Franco, V. Manca, An algorithmic analysis of DNA structure, Soft Computing–A Fusion of Foundations, Methodologies and Applications 9 (10) (2005) 761–768] it was shown to be essential for some informational and computational aspect...