1. The speed of computation is slow, often requiring hours to compute a simple function.
2. The circuits are of high complexity regarding the number of DNA strands.
Duke University researchers introduced an architecture of DNA logic circuits based on single-stranded logic gates using strand-displacing DNA polymerase. The logic gates consist of only single DNA strands, which largely reduces leakage reactions and signal restoration steps such that the circuits are improved in regard to both speed of computation and the number of DNA strands needed. Large-scale logic circuits can be constructed from the gates by simple cascading strategies. In particular, we have demonstrated a fast and compact logic circuit that computes the square-root function of four-bit input numbers.
Duke researchers are working on
* Localized DNA Computation: Faster and Simpler Molecular-Scale Computing
* Programming DNA-based Biomolecular Reaction Networks on Cancer Cell Membranes: localized circuits, molecular reaction networks
* Compact and Fast DNA Logic Circuits Using Strand-Displacing Polymerase and Single-Stranded Logic Gates: logic circuits, enzyme-based circuits
* DNA-based Analog Computing: analog circuits