Genetics - Paper Electrophoresis

Paper Electrophoresis

Teacher: Nancy Gettman
Subject: electrophoresis
Grade Level(s): 9 10 11 12
Target Audience: Biology I, Genetics, Life Science
Materials Needed: adding machine paper, ruler, scissors, tape, larger sheet of paper, graph paper
Class Time: 50 minutes or more
Brief Summary: This activity illustrates the concept of electrophoresis without using expensive equipment.
Student Objective(s): The student will learn from this activity the concept of electrophoresis. This hands-on activity demonstrates the mechanics of electrophoresis without using expensive equipment. The student determines that the use of restrictive enzymes and that the larger the DNA the less it will travel. The smaller the DNA, the farther it will travel in a gel.
Integration (tying it all together): This activity was designed to use as an introduction to electrophoresis as in a genetics class or as a hands-on activity for a regular biology class when no other equipment is available to illustrate the concept. Math is an integrate part of the lab.
Description of Activities:: 1.) Cut a strip of adding machine paper 1.5 meters long for each group.; 2.) Mark one corner 3' (prime) and the other corner 5'.; 3.) Randomly select the letters of each base, (C=cytosine, T=thymine, G=guanine, A=adenine) and write on the edge of the paper starting with the 3'. Four letters should equal 2.5 cm resulting in about 240 letters.; 4.) Write the complementary strand on the opposite side of the paper.; 5.) Using a restrictive enzyme (scissors) cut in half or in fragments at the restrictive site "AT" resulting in stacks of spliced DNA.; 6.) Measure the lengths of the spliced DNA and separate into the piles A) 0 - 2.5 cm, B) 2.5 - 5 cm, C) 5 - 7.5 cm, D) 7.5 - 10 cm, E) 10 - 12.5 cm, F) 12.5 - 15 cm, G) 15 - 17.5 cm, and F) greater than 17.5 cm.; 7.) Every 2 pieces that migrate to any point is equal to .5 cm. Add the centimeters together; i.e., 7 pieces = 1.75 cm. Cut a strip of paper 3 cm wide and the length of the separate pieces added together (1.75 in example). Label each strip.; 8.) Using a larger sheet of paper for the gel, label the top of the paper according to the number of groups in the class. Place a well at the bottom of the paper forming a lane from the number to the well.; 9.) Starting at the well, divide the paper into equal sections A through F and label.; 10.) Have each group attach their pieces of paper (DNA) at the corresponding lengths. For example: for A (0-2.5) 2 pieces of cut DNA; .5 cm. D (7.5-10) = 7 pieces of DNA; 1.75 cm. Continue through all the pieces of DNA.; 11.) To use graph paper instead of the large sheet of paper: For each 2 pieces of cut DNA that migrate to any point, shade in the area of 1 ml. Record the data for each student to plot on a graph paper.
Further Information and References: The idea was observed at a state science convention. The lab was written by Nancy Gettman.

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