The Biochip and Advancements in Medical Treatment
Advances in microchips occur daily, but a recent advance in the area can only be called revolutionary. No, these are not a more advanced breed of thin silicon wafers, better known as computer chips. They are called biochips.
A blending of silicon technology with biology has produced a groundbreaking new technology. It can be used to tell how actively a gene works, whether it carries any mutations, and even aid in the human genome project, a long term project to map the entire human genome. The biochip is a square of glass about the area of a dime. It is carpeted with DNA probes. The probes are oligonucleotides, strands of DNA six to nine bases long. A long strand of DNA of an unknown sequence is to be tested to determine its sequence. First, it is fragmented and then washed over the chip. The fragments only attach to their complementary oligonucleotides on the chip. This is because bases only pair with complementary bases. Adenine bonds with thymine, and cytosine bonds with guanine. The next step is to analyze the reactions between the bases and determine the sequence of base pairs. This will give a clear picture of the formerly unknown DNA. The biochip uses fluorescent tags to determine where unknown fragments attach to their complementary strands on the chip. A microscope attached to a computer "reads" the patterns of fluorescence and gives the sequences of the unknown strand.
Deoxyribonucleic acid, or DNA, consists of various sequences of four organic compounds called bases, and some proteins. Abbreviated, the initials of the bases are A, C, G, and T. The building blocks of all life, they encode thousands of genes. These genes in turn are responsible for directing the construction of proteins which make up cells and control biological processes. The human genome project is a cooperative international effort to "map", or determine the sequence of all the human genes and specify the traits that they control. The mapping and determining the traits part is proceeding much more rapidly than the process of finding the entire sequence of individual letters. The biochip will make it...