Download Process of Electrophoresis

Process of Electrophoresis
Extracted from http://www.bio-rad.com/webroot/web/pdf/lse/literature/1660077EDU.pdf
Video preview
Using a micropipette
http://www.cleanvideosearch.com/media/action/yt/watch?videoId=p-OPOYbeZP0
Agarose gel electrophoresis
http://www.cleanvideosearch.com/media/action/yt/watch?videoId=vq759wKCCUQ
DNA electrophoresis sample loading
http://www.cleanvideosearch.com/media/action/yt/watch?videoId=tTj8p05jAFM
Agarose gel electrophoresis is a procedure used to separate DNA fragments based on their sizes. DNA is
an acid and has many negative electrical charges. Scientists have used this fact to design a method that
can be used to separate pieces of DNA. A solution containing a mixture of DNA fragments of variable
sizes is placed into a small well formed in an agarose gel that has a texture similar to gelatin. An electric
current causes the negatively-charged DNA molecules to move towards the positive electrode.
Imagine the gel as a strainer with tiny pores that allow small particles to move through it very quickly. The
larger the size of the particles, however, the slower they are strained through the gel. After a period of
exposure to the electrical current, the DNA fragments will sort themselves out by size. Fragments that are
the same size will tend to move together through the gel and form bands.
This lab can also be done using “model” DNA (AKA dye). The key difference is that dye molecules are
very similar in size, but they differ in the amount of electrical charges.
Black
Red
DNA Gel Box Filled with buffer solution to conduct electricity.
To conduct current effectively through the gel, the box must be filled with enough buffer so that the gel is
under 1-2mm depth of buffer. Gels using “quick run buffer” can be run at 170V.
Teacher notes below
Teacher notes
Yes can use just food coloring, but it does tend to trail during loading (might set max value at
18microliters
Food coloring Dye concentration suggestions
Darker colors 10-5% food coloring 90-95% water (V/V)
Lighter food coloring 15-10% food coloring 85-90% water (v/v)
Use 0.25X TAE (quick run buffer)
--to prep 0.25X TAE from 50X TAE stock solution
Either from 10ml of stock TAE +1990ml of dH2O or, 1ml of stock TAE +199ml of dH2O
-set up gel boxes mostly full w/ TAE.
Each group gets a small bottle of TAE to add that last little bit of TAE so 1-2mm above
-probably change TAE solution is reusable but will probably need changing every 2-3 labs