Tuesday, November 17, 2009
Visualizing Extracted DNA
I have spent the better part a week extracting DNA from dried tissue samples acquired during my research in the Hartley Wood. There is over 600 specimens in the collection, of which 420 have had their DNA extracted. Now begins the task of confirming the presence of DNA using gel electrophoresis. This is not to say that if DNA is absent using this visual assay that it is physically absent, only that I could not observe the bands created during the electrophoresis process. I have not standardized the concentration of extracted DNA before running the gels and therefore some bands are easy to see and others are quite faint. Again, this assay is only being performed as a troubleshooting tool if my PCR products are not visible when run out on a gel. Some of these terms might be foreign to some of you and I apologize, still the main point I am trying to express is the tedious nature of describing my collection through molecular techniques. In today's field of mycology, these molecular characteristics (DNA sequences) are valuable sources of information used to identify and describe relationships between groups or species of fungi. To the right is the image of a gel that has been stained with Ethidium bromide and photographed under UV illumination. The "L" in the far left lanes are the 1Kb ladder used as a reference of size and the numbers above the remaining lanes indicate the extraction codes for the specimens.