Processing DNA molecules as text

Polymerase Chain Reaction (PCR) is the DNA-equivalent of Gutenberg’s movable type printing, both allowing large-scale replication of a piece of text. De novo DNA synthesis is the DNA-equivalent of mechanical typesetting, both ease the setting of text for replication. What is the DNA-equivalent of the word processor? Biology labs engage daily in DNA processing—the creation of variations and combinations of existing DNA—using a plethora of manual labor-intensive methods such as site-directed mutagenesis, error-prone PCR, assembly PCR, overlap extension PCR, cleavage and ligation, homologous recombination, and others. So far no universal method for DNA processing has been proposed and, consequently, no engineering discipline that could eliminate this manual labor has emerged. Here we present a novel operation on DNA molecules, called Y, which joins two DNA fragments into one, and show that it provides a foundation for DNA processing as it can implement all basic text processing operations on DNA molecules including insert, delete, replace, cut and paste and copy and paste. In addition, complicated DNA processing tasks such as the creation of libraries of DNA variants, chimeras and extensions can be accomplished with DNA processing plans consisting of multiple Y operations, which can be executed automatically under computer control. The resulting DNA processing system, which incorporates our earlier work on recursive DNA composition and error correction, is the first demonstration of a unified approach to DNA synthesis, editing, and library construction

Chemically-Derived Cuo/In2O3-Based Nanocomposite For Diode Applications

Nowadays, oxide-based semiconducting nanostructures are widely regarded as one of the most essential elements of the modern semiconductor industry and for a number of advanced technological functions in electronics and optoelectronic platforms. In this regard, a CuO-based nanocomposite was synthesized through a facile surfactant-free wet chemical strategy, and its potential for photoelectronic applications has been demonstrated. The nature of the composite phase and its other structural characteristics were studied in detail using Raman and X-ray photoelectron spectroscopic tools. The particulate characteristics of the composite were inferred using transmission electron microscopic measurements. Room temperature luminescence measurements revealed that the optical activity of the composite spreads across the red and near-infrared region of the electromagnetic spectrum through corresponding transitions. The optoelectronic capabilities of the processed composite were investigated through fabricating a CuO composite/ZnO nanowire-based p-n heterostructure and studying its associated current-voltage (I-V) characteristics under photon illumination. The nature of charge carriers, flat band potential, charge transfer resistance and carrier density were also studied individually and collectively for each component comprising the heterostructure through Mott-Schottky and Nyquist type impedance plots