Molecular Cloning: A Laboratory Manual has always been the laboratory mainstay for protocols and techniques. It has a pure-bred ancestry, and the new edition does not disappoint. (It) includes information panels at the end of each chapter that describe the principles behind the protocols.... The addition of this information extends Molecular Cloning from an essential laboratory resource into a new realm, one merging the previous prototype with a modern molecular monograph...the next generation of Molecular Cloning not only carries on the proud heritage of the first two editions but also admirably expands on that tradition to provide a truly essential laboratory manual. Trends in Microbiology
As in benzene, in substances such as beta carotene , chlorophyll , or heme , some electrons in the π orbitals are spread out in molecular orbitals over long distances in a molecule, resulting in light absorption in lower energies (the visible spectrum ), which accounts for the characteristic colours of these substances.  This and other spectroscopic data for molecules are well explained in MO theory, with an emphasis on electronic states associated with multicenter orbitals, including mixing of orbitals premised on principles of orbital symmetry matching.  The same MO principles also naturally explain some electrical phenomena, such as high electrical conductivity in the planar direction of the hexagonal atomic sheets that exist in graphite . This results from continuous band overlap of half-filled p orbitals and explains electrical conduction. MO theory recognizes that some electrons in the graphite atomic sheets are completely delocalized over arbitrary distances, and reside in very large molecular orbitals that cover an entire graphite sheet, and some electrons are thus as free to move and therefore conduct electricity in the sheet plane, as if they resided in a metal.