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Description of Laboratory Session
Consult the "Forensic DNA Fingerprinting Kit" TA Manual (PDF File)
DNA Fingerprinting Gels (Bio-Rad Laboratories)
Overview of DNA Fingerprinting Lab
Using DNA as evidence, students figure out for themselves, "Who done it?"
DNA evidence assists in criminal, missing person, mass disaster, and paternity cases. It can be used to identify a perpetrator or exonerate the innocent. Using real DNA as evidence, students play the role of crime scene investigators.
Restriction enzymes are essential tools for molecular cloning and the mapping of genes and genomes. They are also used in genetic engineering to create recombinant DNA molecules for transforming bacterial, plant, or animal cells.
Restriction enzymes recognize specific double-stranded DNA sequences and cut by making two incisions, one through each of the phosphate backbones of the double helix. The chemical bonds that the enzymes cleave are easily reformed by DNA ligases, so that restriction fragments carved from the DNA of different organisms can be spliced back together, creating new hybrid organisms.
In this lab, students observe the effects of two DNA restriction enzymes on a series of plasmid DNA samples. The six DNA samples in this kit are plasmids engineered to mimic the natural variations in DNA that exist between one human being and another.
One DNA sample has been collected from a "crime scene" and five samples have been obtained from various "suspects". Each sample is digested using a mixture of two DNA restriction enzymes generating a distinct set of DNA fragments for each sample. The resulting DNA fragments are separated by agarose gel electrophoresis and visualized using Bio-Rad's revolutionary Fast Blast DNA stain.
* (Source: Bio-Rad Laboratories)