Diagnostic tools for measuring cell free nucleic acids; What can we expect from the next decade?

Abstract
The presence of cell free nucleic acids within bodily fluids offers samples for non or minimally invasive collection as well as numerous unique possibilities for diagnostic and prognostic analysis. The association of this fraction with rapid cellular growth or breakdown, through apoptosis and/or necrosis, results in a natural enrichment of sequences associated with pathology, for example associated with inflammation or tumour growth, or foetal development. Consequently cell free nucleic acids offer the potential for foetal analysis or tumour and pathogen diagnosis far earlier and far less invasively that is currently possible. While these facts offer much optimism for newer diagnostic and prognostic assessment, targeting cell free nucleic acids poses some unique challenges, which will need to be tackled if the potential of this nucleic acid fraction is to be maximised. Here we discuss the spectrum of considerations when measuring cell free nucleic acids and outline some of the recent technologies that will faciliate their translation to clinical diagnosis.