Theory/Modelling

Nucleic acid analysis has enhanced our understanding of biological processes and disease progression that helps elucidate the association of genetic variants and disease. The need for rapid and high sensitivity nucleic acid detection continues to grow for applications where providing timely results with limited resources remains challenging. Microfluidic and single molecule methods offer alternative solutions to achieve rapid and high sensitivity nucleic acid detection. Solution-based single molecule detection strategies enable high detection sensitivity without the need for nucleic acid amplification and are instead limited only by the volume of sample that can be efficiently screened. Such detection methods couple nicely to microfluidic analysis because microfeatures can be designed to match the fluidic analysis volumes with the single molecule detection volume for highly efficient sample screening. We have demonstrated that the coupling of microfluidics and cylindrical illumination confocal spectroscopy (CICS) enables highly sensitive detection of genetic and epigenetic makers in liquid biopsy. By further coupling CICS with free solution hydrodynamic separation (SML-FSHS), we can size separate individual nucleic acid fragments independently of fluorescence and provide highly quantitative analysis over a large dynamic range by counting single molecule bursts.