The global area under genetically modifi ed crops has increased from 1.7 million hectares in 1996 to over 100 million hectares in 2006, and nearly one-third of the area under transgenic crops was in developing countries ( James, 2007). The major transgenic crops include soybean (60%), corn (23%), cotton (12%), canola (5%), and potato (~1%). The major traits include herbicide tolerance (71%), insect resistance (28%), and quality traits (1%). More than 8 million farmers have benefi ted from this technology, and 90% of the benefi ciaries are the resource-poor farmers in developing countries. Although considerable progress has been achieved in the development of analytical methods for detection of genetically modifi ed food based on polymerase chain reaction (PCR), several other analytical technologies, including mass spectrometry, chromatography, near infrared spectroscopy, micro fabricated devices, and DNA chip technology (microarrays), can also be used for monitoring and detection of genetically modifi ed food. So far, only PCR-based methods have been accepted for regulatory purposes. Monitoring and detection of genetically modifi ed crops consists of three distinct steps, detection, identifi cation, and quantifi cation.