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DNA Sequencing and Digital DNA


DNA Extraction
Gel Electrophoresis
PCR (Polymerase Chain Reaction)
DNA Sequencing
Large Scale Sequencing
Digital DNA

DNA Extraction

DNA Image DNA is a long and thin macromolecule with length up to 2 meters but only 10-7 cm in width. It is invisible to the naked eyes. However, the atomic force microscope (AFM) has been used since the mid 1980s to produce topographic maps of nanostructures including DNA. In atomic force microscopy, an extremely sharp tip senses the atomic shape of a sample while a computer records the path of the tip and slowly builds up a three-dimensional image. One of the first images of DNA is shown in Figure 01, where the white blobs are repairing proteins bound to the DNA. There is a crude method to extract DNA from the cells. The result doesn't show the individual macromolecule but appears in the form of cloudy substance. The steps, which are applicable at home and in school, are outlined in the following:

Figure 01 DNA Image
[view large image]

A string of DNA is just another form of life-less macromolecules. A living cell manages to use a bunch of them for growth and replicate (see "Recreation of Life"). Since units of similar entity with different property or configuration can be used to represent another ensemble of things, the basic units of DNA are another kind of medium to represent a text or an image file. The sections below summarize the essence on its synthesis, retrieval, and other aspects of the subject.