I have been doing a lot of research on my project as I have been waiting for the rest of my supplies to come in (which, I'm excited to report that they are almost all in, thanks Matt!!). One of the most important process's to my project is called PCR, Polymerase Chain Reaction.
So what is PCR? Well it is the process of replicating or copying a small portion of a single side of the DNA double helix, outside of the body. Sounds complicated right?? Well our body makes copies of existing cells every single day and I have been given a great protocol to do this.
The process beings with unwinding the DNA double helix, because as you all know, it is in a ladder shape and it is coiled extremely tight so a process of 'melting' must take place. Where the twisted ladder is uncoiled to look like a regular ladder by adding primers and reagents to the sample. The sample is then heated and the weak hydrogen bonds are broken and the ladder-like structure splits down the middle making two single strands. The mixture now needs to be cooled (called the anneal process). According to Saferstein, a primer is added to the mixture which are short sequences of nucleotides, (pg. 270 Criminalistics: An Introduction to Forensic Science) that attach to the beginnings of the separated single strands of DNA. This is where the replication process begins and complete copies of DNA are formed. The last stage is the extension stage where the mixture is heated again and enzymes attach to the complimentary base pairs of DNA (Adenine, Thymine, Cytosine and Guanine).
Here is my illustration of how this process works.
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