A DNA fingerprint was first introduced as evidence in 1988 and was said to be the greatest advance in forensic science since the late 1800s. Everyone has different repeating sequences of nucleotides in their fingers, so fingerprints can be used to identify any individual.
Purpose: The purpose of this lab is to explore the repeating short sequences of nucleotides in human fingerprints and to learn more about DNA.
Materials: Materials for the first procedure include a microwave oven, one agarose pour, one comb, electrophoresis gel tray, one roll labeling tape, micropipette, micropipette tips, aluminum foil, food dye in micro-tubes, plastic bags or wrap, lab write-up, and toothpicks. Materials for the second procedure are three power supplies, one electrophoresis chamber, one prepared gel, one micropipette, micropipette tips, TBE buffer, and a micro-tube rack with DNA tubes. Materials for the third and last procedure include a staining tray, methyl blue/CarBLU©, latex gloves, water, “light box”, and your lab write-up.
Procedure 1: First, melt agarose pours in the microwave. Next, carefully seal ends of the gel tray with tape. After that, carefully align comb and place tray out of the way on the lab table so that when the hot agarose is poured, it will be undistributed. Fourthly, you remove the cap and carefully pour hot agarose into the taped tray while the agarose is still hot. Allow 10-15 minutes for the gel to solidify. Lastly, carefully remove the comb from the gel.
Procedure 2: First, cut a notch in the upper left hand corner and place it in the electrophoresis chamber. Then fill the electrophoresis chamber with TBE buffer (this can be reused) until it just covers the top surface of the gel. Next, locate the micro-tubes labeled Suspect 1(blue cap), Suspect 2 (green cap), Evidence (clear cap), and