Restriction Enzymes and Washi Tape

We're going to do the gel electrophoresis lab in AP Biology this coming week. I love for students to have a visual of what is happening when we get DNA ready for electrophoresis. This visual also helps them as we discuss why some pieces of DNA move faster than others and therefore give us distinct bands.

For our pre-lab conceptual practice we use toilet paper to represent DNA, washi tape to represent the location of specific palindromic restriction sites, and scissors labeled with specific washi tape to represent the restriction enzymes. Students take turns using the restriction enzymes to cut the DNA and then we determine the number and placement of bands on a gel using the number of toilet paper squares that are in each cut piece of DNA. The idea for this came this video on Vimeo.

 

For students to represent their electrophoresis gels, I made a template in Google Slides that I can project onto the whiteboard in the classroom.  Students can mark where they think the toilet paper DNA will migrate to.  Then I switch to the second slide that will reveal the banding pattern of the "criminal".  I like to wait to show that until last, otherwise they figure out who the criminal is before they finish getting all the bands up.  This way, the suspense lasts until all the bands are drawn on the board.

The template in Google Slides also includes the sketch of locations of each of the restriction sites.