The proposed methodology, “Laser-Assisted DNA Optical Mapping (LADOM)”, allows retrieving the barcode of single molecules of DNA in real time, as they flow through a nanochannel in a fluidic device. It combines a cheap device fabrication, flexible DNA labelling (customizable for different applications), microscope- and camera-free set up, a read-out sensitive to single molecules, very high throughput (hundreds of molecules per minute), ability to detect very small fragments, and no limitation for the maximum molecule’s length, what is especially interesting for applications dealing with ultra-long intact, genomic DNA. The simple volumen used is just a few uL (typically 3 uL, could be even less), and, since the analysis is performed at the single molecule level, the amount of material needed to obtain preliminary trends is also very low.
One of the potential application fields of this technology is liquid biopsy. Liquid biopsy is a powerful, emerging method, which will be the future of cancer monitoring. It holds the promise to replace conventional biopsy, where a needle is used to extract tissue from the affected organ. Instead, in liquid biopsy, the material used for the screening is obtained from body fluids –mainly blood- where it is possible to find circulating tumor material (vesicles, cells or DNA and RNA). But this liquid biopsy still has (technical) challenges to overcome before it can be routinarily used in the clinics. One of the main technical challenges is the very low amount of material available for the analysis, which comes surrounded by plenty “noise DNA” from healthy cells. And the DNA analysis still depends on expensive methods, not easily accessible.
In this project, our goal is to show the proof of concept for using our single molecule analysis method to analyze the DNA of samples with the potential of being used for cancer monitoring.
