Restriction Enzymes and Plasmid Mapping
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. With the curriculum in this kit, students also have the opportunity to read plasmid maps and predict the sizes of DNA fragments from restriction enzyme digests prior to performing the lab. They can go one step further and use restriction digest maps of lambda bacteriophage genomes (provided in the kit curriculum) to design novel plasmids. In the process of doing these extension activities, students learn how restriction enzymes function and how they are used in genetic engineering. Use this kit to open the door to rich discussions about the scientific, ethical, and legal implications of forensics, DNA profiling, and genetic engineering.
