Introduction to nanopore sensing
- Biological nanopores
- Solid-state nanopores
The GridION™ system
The MinION™ device: a miniaturised sensing system
Analytes and applications: DNA, RNA, proteins
Fields of use
Oxford Nanopore's first generation of technology uses bespoke, proprietary pore-forming proteins to create pores in membranes. Pore-forming proteins are common in nature.
For example, the protein α-hemolysin and similar protein pores are found naturally in cell membranes, where they act as channels for ions or molecules to be transported in and out of cells.
α-hemolysin is a heptameric protein pore with an inner diameter of 1 nm, about 100,000 times smaller than that of a human hair. This diameter is the same scale as many single molecules, including DNA. The pore is highly stable and has been characterised in great detail by Oxford Nanopore and our collaborators. The Company has optimised the large-scale production of this and many other bespoke pore-forming proteins, each of which have different characteristics suitable for different applications.
Adaptation of protein nanopores for the identification of single molecules
Protein nanopores can be adapted at Angstrom-level precision using protein-engineering techniques. Specific adaptations can be designed so that the nanopore is a sensor for a range of specific molecules. Techniques include:
- Changing the architecture of the internal structure of the nanopore so that it affects the passage of an analyte through the pore.
- The incorporation of a specific binding site within the nanopore, that will bind transiently to the molecule being detected. This might be a cyclodextrin in the case of DNA bases, or other adapters for other small molecules.
- The incorporation of a DNA probe to detect an organism with the matching DNA code.
- The attachment of a molecular motor – for example a processive enzyme – for the analysis of polymers such as DNA.
- The attachments of ligands to the nanopore, to bind with target proteins outside the pore.
Oxford Nanopore has developed proprietary methods of designing bespoke nanopores, programming bacteria to produce the nanopores and purifying the resulting solution to generate high-yield novel nanopores in solution. This end-to-end process can now be performed in a number of days.
The Company has also developed proprietary electronics that enable multiple nanopore sensing experiments to be performed in parallel, the data collected, and analysed in real time through modular instrumentation. This is the GridION™ system.