chapter  Chapter 7
28 Pages

DNA-Based Methodologies

ByMarta Muñoz-Colmenero

Deoxyribonucleic acid molecule (DNA)-based techniques used for food traceability and food safety are based on polymerase chain reaction (PCR), which results in the amplification of a specific region of the genome delimited by previously selected primers. This technique presents a high potential for application due to its speed, simplicity, sensibility, and specificity in obtaining a large number of copies of target sequences from a minimal amount of sample tissue. One of the simplest and cheapest methods to visualize the PCR product is by using a conventional gel electrophoresis. These approaches use polyacrylamide gels that include a denaturing agent, usually urea or formamide, for creating a denaturing gradient —the most commonly used method—or increase the temperature during the process. Amplified fragment length polymorphism has a high probability of detecting species-specific or population-specific polymorphisms because it generates hundreds of genetic markers. It is based on the digestion of DNA present in the cells using several restrictions enzymes.