Geneticist for a Day
Goal: Have students be able to evaluate a gel electrophoresis in a research science setting

Materials: Pen or pencil, paper

The scenario: You are a scientist studying the mouse gene smu, which codes for the protein SMUase. You want to collect a lot of SMUase, but the mice do not make the protein quick enough, so you decide to create a plasmid.

You make the plasmid with the smu gene, and other necessary markers, and decide to insert it into e. coli bacteria. You heat up the bacteria to get the plasmid inside and near the DNA, but you cannot be sure that the plasmid has inserted itself into the E. coli’s DNA.

You know that your gene contains the sequence GGGAATTCCG, so you decide to perform an electrophoresis on the e. coli DNA, then use a probe to determine if your gene has been inserted into the e.coli DNA.

The DNA the probe binds to is in red. The size marker is in blue.

Gel Electrophoresis
Click for a larger picture

Questions:

What sequence would the probe have?

What must be done to the e. coli before the electrophoresis?

Did your plasmid make it into the DNA? Why or why not?