The separation of
DNA (not a double but a single strand) of the same length starts with
synthesized DNA that is dyed so that the capillary machine detector can detect
the separated DNA at the end of the process. Scientists are aware of how to
separate DNA with different lengths, but what they do not know and what my
internship is focused around is how to separate DNA of the same length. This
can simply not be done by adding common separating polymers to the tube, but by
adding one of the four bases (adenine, guanine, thymine, and
cytosine) which helps to differentiate the speed at which the DNA sample hits
the cathode end (due to the phosphate group attached to the DNA which gives it
a negative charge). Why adding the bases helps separate the genes is unknown
and there is currently a limit to how many parts the DNA can be separated into—as
of now, it can be separated into 7 pegs.
After understanding all this, I was then explained to about the
lab procedures that I would be performing. The graduate student that helped me,
Yolanda, walked me through and we prepared the DNA test samples that will go in
the machine for analysis. At the end of my time, I was amazed at how far I had
come (and it was only the 2nd time here) as just 2 weeks ago, I had
no idea what capillary electrophoresis was and as to me, it sounded like
something in another language. I am looking forward to my next meeting, as I
will be able to apply what I have learned today and play an even greater role
in preparing the test samples for the lab.
Great blog post, Christi. You provide lots of information in a convincing way, and you create a nice sense of your project. Best of all, you point out what is coming up. Keep up the great effort!
ReplyDeleteWhat is a "peg?"
When I said "peg" I was referring to the high points in the graph attained from the capillary machine. Every so often, there would be a peak in the graph and that peak is what I referred to as a "peg".
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