DNA sequencing

DNA Sequencing 

DNA Sequencing focuses on the biochemical methods for determining the order of the nucleotide bases, thymine, guanine, adenine, and cytosine, in a short polymer of two to twenty nucleotides. The DNA sequence equals the genetic heredity information in its nuclei, mitochondria, plasmids, and chloroplasts which links to the developmental programs of all living organisms.

The DNA sequence is useful in studying fundamental biological processes and in applied fields such as forensic or diagnostic research. The arrival of DNA sequencing has significantly accelerated the research and discovery of biology. Sequencing at a rapid speed helps us attain modern DNA sequencing technology that has been helpful in the large-scale sequencing of the human genome, in the Human Genome Project. 


Identifying Sequences in DNA - DNA Fingerprinting

1. Restriction Fragment Length Polymorphism (RFLP)- used to identify locations and number of restriction sites. DNA fingerprinting.

        a. cut DNA using restriction enzymes

        b. Everyone has different DNA, thus length and number of fragments differ

        c. Separate fragments using gel electrophoresis = DNA fingerprint

              WHY:---> ID criminals

                        ---> ID remain

                        ---> Parents

                        ---> Genetic Disorder


   2. Polymerace Chain Reaction (PCR) - Used when DNA Sample is Small

      a. Add DNA polymerace and all 4 nucleotides to DNA

      b. Incubate a few hours = millions of copies

The DNA of each human cell contains 6 x 109 base pairs. An example of a structural gene is the beta chain of hemoglobin, it is identical in a large portion of people today. Although the information is true, long stretches of DNA do not code for anything. They are free and able to mutate in great amounts. If we could read the entire DNA sequence in each human, it would be certain that we would never be able to find two that were identical unless the samples were given from identical siblings. This is because they were derived from a single zygote.

So each person's DNA is as unique as a fingerprint.








C. Davis©2007


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