Introduction to PCR — The Polymerase Chain Reaction
You are about to perform a procedure known as PCR
to amplify a specific sequence of
your own DNA in a test tube. You will be looking for a particular piece of DNA that is present
in the genes of many, but not all, people. Analysis of the data generated in this laboratory
will enable you to determine whether or not you carry this specific DNA sequence.
, composed of DNA, is our hereditary code. This is the so-called
blueprint that controls much of our appearance, behavior, and tendencies.
is the study of genes and the molecular details that regulate the flow of genetic
information from DNA to RNA to proteins, from generation to generation.
uses this knowledge to manipulate organisms’ (microbes, plants, or animals) DNA to help
solve human problems.
Within the molecular framework of biology, DNA, RNA, and proteins are closely tied to
each other. Because proteins and enzymes ultimately play such a critical role in the life
process, scientists have spent many lifetimes studying proteins in an attempt to understand
how they work. With this understanding, it was believed we could cure, prevent, and
overcome disease and physical handicaps as well as explain exactly how and why
organisms exist, propagate, and die. However, the complete answer to how and why does
not lie solely in the knowledge of how enzymes function; we must learn how they are
made. If each enzyme is different, then what controls these differences and what is the
blueprint for this difference? That answer lies within our genome, or genetic code.
Thus, you may realize why researchers today, in an attempt to understand the
mechanisms behind the various biological processes, study nucleic acids as well as proteins
to get a complete picture. In the last 20 years, many advances in nucleic acid techniques
have allowed researchers to study the roles that nucleic acids play in biology. It took the
imagination and hard work of many scientists to reveal the answers to one of the most
mysterious puzzles of life — understanding the mechanisms that control how DNA is
translated into proteins within living cells.
Before Beginning This Lab, See If You Can Answer the Following
How is DNA faithfully passed on from generation to generation? What causes genetic
disease in some people but not others? How do scientists obtain DNA to study? What
secrets can DNA tell us about our origins? What human problems can an understanding of
DNA help us solve? Should we unlock the secrets held in this most basic building block of
PCR Set the Stage for a Scientific Revolution
In 1983, Kary Mullis
at Cetus Corporation developed the molecular biology technique
that has since revolutionized genetic research. This technique, called the
(PCR), transformed molecular biology into a multidisciplinary research field
within 5 years of its invention. Before PCR, the molecular biology techniques used to study
DNA required such a high level of expertise that relatively few scientists could use them.