DNA sequencing

DNA sequencing is the process of determining the exact order of nucleotides (G, A, C, and Ts) for a particular organism. Each organism has a unique sequence that differs not only between species but also (less) between individuals. Individuals that are more closely related will have more similar sequences than individuals that are less related. With the exception of identical siblings (maternal twins) and propagation by cloning, all plants and animals have unique DNA sequences.

The technology used for DNA sequencing has accelerated at such a pace in the last few years that we can now determine the sequence of millions of base pairs in one day. The advancement of DNA sequencing technology will soon make current molecular biology technologies, such as molecular markers and gene mapping, obsolete. Having the DNA sequence in hand renders other molecular technologies unnecessary.

Studying DNA sequences can illuminate both how organisms are the same (e.g., how genes function in a pathway) and how they are different.

Resources:
University of Nebraska has a nice animation depicting the PCR process (and many others):
http://croptechnology.unl.edu/download.cgi