PCR-free method detects high frequency of genomic instability in prostate cancer

Since the introduction of Polymerase chain reaction (PCR) techniques, it has been the method of choice for many tumour instability studies. PCR-based methods are useful for the study of small-scale somatic alterations. However, these methods often underestimate the frequency of mutations in heterogeneous tumour genomes. Thus in such cases, sequencing of individual clones may prove more fruitful. The paper by Makridakis et al (2009) investigates the use of a random cloning/sequencing method to identify genomic instability in prostate cancer. This method involves the random cloning of DNA into plasmid vectors, and the subsequent transformation of competent E. coli cells, for a non-PCR based method of cloning. Whilst cloning DNA using plasmid vectors is not a new technology, the combination of random cloning and sequencing of DNA for the use of genomic instability studies is a novel idea. Using this random cloning/sequencing method the authors reported findings that were several orders of magnitude higher than those reported previously.

Emily Chan