Post-PCR analysis

It should be noted that the PCR process itself is usually merely
a starting point for an investigation by providing a sufficient
quantity of DNA for further analysis. After completion of
thermal cycling, the first step in analysis is to determine the
success of amplification using agarose gel electrophoresis
(AGE). The DNA is separated within the gel depending on its
size; large DNA molecules travel slowly through the gel in
contrast to small DNA molecules that travel faster. The DNA is
detected within the gel with the use of a fluorescent dye
(ethidium bromide) as a pink fluoresent band when
illuminated by ultraviolet light. By varying the agarose
concentration in the gel, this approach can be used for the
analysis of PCR products from less than 100 to over 10 000 base
pairs in size.