Detection of Genetic Alterations by Nucleic Acid Analysis: Use of PCR and Mass Spectroscopy-Based Methods

Cell free circulating DNA, isolated from blood has emerged as a potential biomarker in oncology. There has been also considerable progress towards theranostic application of circulating DNA. These applications were enabled by the increased use of the PCR technique and its derivates. PCR assays have become a widely used method for the quantification of circulating DNA in either plasma or serum samples. Moreover, PCR amplification is the basic method implicated in the majority of the circulating DNA analytical methods. This review focuses on the PCR and Mass-spectrometry methods developed to detect circulating DNA alteration from blood, in evolving applications such as cancer diagnostic tools. This review also gives advices and guidelines for designing PCR experiments with the specific requirements of circulating DNA. The concentration of circulating DNA, especially mutant circulating DNA, fragments can be too low for accurate measurements with other spectrophotometric methods. However, the accuracy, the high through-put and multiplexing capabilities of mass spectrometry becomes an interesting tool for the quantification as well as for the characterization of circulating DNA.