|MadSci Network: Biochemistry|
Amy, Carolina Biological Supply Company (www.carolina.com) sells a DNA forensics kit for $40.00 (includes DNA fragment, electrophoresis equipment and supplies). Alternatively, I can think of a fingerprinting simulation activity that I saw at the National Museum of American History in Washington, DC last month. You could design a similar activity yourself. Come up with a crime plot featuring a set of fictitious persons (one of them is the suspect). You want to find out if the DNA fingerprint of one of these persons matches the one which was left at the crime scene by the suspect. For each person, make a set of “DNA fragments” that are specific for that person. You can make these out of mat board, strong cardboard or wood. Glue flat magnetic tape or small, round magnets (available in craft supply stores) on the bottom of one or two selected fragments for each person. Make sure that for two persons (suspect and one of your fictitious persons) the so marked fragments are identical in size and number. These magnetic fragments are the ones that carry the specific sequence we are looking for in this simulation. To find the fragments that carry the magnets (= specific “sequence”), use very small probe fragments that are glued to a magnet as described above. You will need many of these to tag all those DNA fragments that carry the specific “sequence”. Sort each person’s fragments by size from largest to smallest (= simulation of separation by gel electrophoresis), with fragments of the same size placed at the same position. Now use your probe fragments (the small ones with the magnets) to find those fragments that carry magnets and compare which the pattern of tagged fragments for each person. It should be evident which person’s pattern matches that of the suspect (same number and size of tagged fragments). Hope this is sophisticated enough. Sabine Heinhorst
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