Curriculum Details

1. Bacterial Genetic Transformation
2. Protein Purification: Column Chromatography
3. DNA Restriction Analysis (DNA Fingerprinting)
4. Amplification and Analysis of Human DNA by PCR
5. Protein Electrophoresis (SDS-PAGE)
6. Bioinformatics
7. Immunology
8. DNA Microarrays and Gene Expression
9. RNAi and Gene Silencing

Amplification and Analysis of Human DNA by PCR

The technique called Polymerase Chain Reaction, or PCR, is now widely used in many areas of research to amplify DNA samples for study. The reaction principle involves repeatedly denaturing the DNA double helix using high temperature, followed by the replication of both strands using a heat-stable form of DNA polymerase first isolated from bacteria living in the near-boiling environment of hot springs in the western United States. Within just a few hours, this method yields millions of copies of the template DNA molecule. Molecular biologists rely on PCR to find the specific genes they are looking for in many different species and to make many copies of a piece of DNA they want to investigate. Forensic scientists use it to identify suspects and victims based on their "DNA fingerprint." PCR is also used in disease diagnosis, evolutionary genetics, and genome sequencing. If you have seen Jurassic Park, you will remember that the creation of this famous dinosaur park was based on the technique of PCR.

Many commercial applications of PCR are being developed, such as rapid detection of disease-causing mold in hospital settings using "bio-chips" that incorporate PCR through nanotechnology. Scientists know that human DNA samples from different individuals actually have more similarities than differences, but we also know that many segments of our chromosomes show great diversity. Two of these polymorphic ("many forms") segments are the objects of this lab sequence. How do scientists obtain DNA samples for such comparative study? How does the Polymerase Chain Reaction allow rapid copying of DNA in order to obtain enough sample for lab analysis? In this lab sequence, we will focus on two separate human chromosomes in which to study the occurrence of repeated DNA segments (called Alu repeats and VNTRs) that we inherited from our parents. We will identify our own genotypes anonymously in order to study their relative frequencies in the human population, and we will share this data on a national computer data base for population-level study. These subtle variations in our DNA provide evidence about our ancestry, as well as the basis of personal identification via DNA fingerprinting.