01/09/13

I was not able to go to my internship because Yolanda [my mentor] was busy.
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        Although I could not go to my internship last Wednesday, I was able to learn about the history of capillary electrophoresis. Historically, DNA sequencing products were separated using gels (like those I have talked about in my previous post) that had to be manually poured between the two glass plates. Capillary electrophoresis was introduced as an novel and automated alternative to slab gel electrophoresis 30 years ago by Jorgensen. By 1989, Bob Brownlee and his coworkers introduced the first commercial instrument for quick and high resolution capillary electrophoresis separation. With the introduction of capillary electrophoresis, work has been greatly facilitated. Due to the reason that you don't need to pour the gels with this method, DNA sequence analysis has been made a lot easier. In addition, this method is far more time efficient as one is able to process more samples at once. The currently used routine Sanger based methods in conjunction with the capillary electrophoresis can directly sequence up to 1000 nucleotides in length in a single reaction. 
          Although there are a lot of positive aspects of the current technology, the cost of sequencing using capillary electrophoresis is quite expensive, costing around $0.02 per base. Just by itself, this number to some, might seem incredibly small and thus contradictory to my previous assertion. However, when calculated, the expense comes out to be $60 million dollars to sequence a human genome. (We are able to calculate this cost because it is known that one human genome contains 3 billion bases.) With the increasing importance of new sequencing and re-sequencing efforts, novel technologies have been arising to replace the currently used methods, promising orders of less expensive sequencing costs per genome--with the goal of $1,000 by the year 2014. According to writers of the article "DNA Sequencing by Capillary Electrophoresis"Barry L. Karger and Andras Guttman, "For the future of personalized medicine, especially for multifactorial diseases, everyone's genome will be sequenced...with a likely cost of several hundred dollars per genome".