Information Technology Reference
In-Depth Information
2.5
PCR and XPCR Protocols
Polymerase Chain Reaction process (PCR) is one of the most important and efficient
tools in biotechnological manipulation and analysis of DNA molecules, where the
polymerase enzyme implements a very simple and efficient duplication algorithm
on double oriented strings. Kary Mullis discovered this method in 1983 [56], and
for this reason, the Nobel Prize in chemistry 1993 was awarded to him (jointly with
Michael Smith for contributions to site-directed mutagenesis).
The main result of PCR is the
exponential amplification
of target double strands
having a given sequence of bases. As will be explained in this section, in the PCR
process, an initial number of target double strands (even only one of them) provides
a final number of them which is a product of the initial number by a multiplicative
factor consisting of a power of the times a basic PCR step is repeated. The bilinearity
of DNA molecules and the antiparallel orientation of their two linear components
are essential aspects of the logic underlying PCR. The computational schema of
PCR in TTL notation is given in Table 2.4, while its combinatorial schema in terms
of string transformations is given in Fig. 2.33.
Fig. 2.33
The schema of Polymerase Chain Reaction
