INTRODUCTION

Arguably the most important conceptual foundation of modern biology is that genetic information is essentially digital in nature. As it happens, the information technology organisational paradigm, built as it is on the special semiconductor properties of silicon, is a convenient framework for a modern understanding of cell and molecular biology and biotechnology, based as they are on the special properties of carbon, and vice versa. Just as a strategic understanding of the basis of information and communication techno - logy (ICT) is becoming an essential life skill in modern society, so a strategic understanding of the conceptual basis of molecular medicine is becoming an essential life skill for virtually all medical practitioners. The analogy of computer viruses, which traces its origins to the 1970s, introduced a useful model for the understanding of both information technology in the language of biology and molecular biology in the language of information technology. The ICT analogy is also a useful conceptual framework for the understanding of disease in a wider setting, because many noninfectious diseases are also ultimately caused or driven by inherited or acquired abnormalities in sequences of digital information. Increasingly, practical use is being made of this concept in the diagnostic process, by applying a small set of tools to identify such disease-causing digital sequences across a wide variety of diseases, whether infectious or otherwise.

Multicellular organisms are each clones of a single cell, of which the genome, normal or abnormal, is effectively the digitally encoded design blueprint for the whole organism. The genome of any organism, be it a micro-organism, plant or animal, is the sequence of the fundamental digital units of information that constitute the specification for the construction and function, or in the case of inherited disease, dysfunction, of that organism. Disease caused by infectious microorganisms can be diagnosed by demonstrating digital sequences that define the presence of those organisms in a highly specific way that not only demonstrates the unambiguous presence of particular organisms, such as HIV, but also often contains the additional information that specifies drug resistance, virulence, etc.