Gel electrophoresis

• What is the purpose of gel electrophoresis?

  Used to sort DNA strands according to length
• What acts as a filter?

  The gel - it sorts the DNA strands
• How is the agarose different to jell-o?

  Its like a sponge made of jell-o with many small holes in it. We place DNA sample into holes at one end of the gel
• What is the electric current for?

  To move the DNA strands through the gel filter.
• Why are DNA fragments drawn towards the positive pole?

  Because DNA is negatively charged
• What is the purpose of the loading buffer?

  The buffer conducts the electrical current from one end of the gel to another & keeps gel from drying out during the experiement.
• What is the name of the holes left in the gel as it cools in which the DNA is loaded?

  Wells
• What des the DNA size standard contain? What is its purpose?

  Contains DNA of known lengths. Running in on the gel will give a reference by to estimate the lengths of DNA strands in your sample.
• How do you know when the current is running?

  In the gel box, check for tiny air bubbles coming out of the electrodes at both ends of the electrophoresis box.
• Why do the longer DNA strands migrate the least?

  Short DNA strands move faster and further than longer DNA strands, in the same period of time.
• Why is ethidium bromide used to stain DNA?

  It binds to the DNA and shows up under the fluorescent light. We cant see single DNA strands, but we can see larger groups of stained DNA strands. these groups will show up as bands in the gel.
• Why is it necessary to avoid contact with ethidium bromide?

  Because it binds to DNA it can damage DNA in your cells, so wear gloves