TU Delft: researchers develop a new way to analyse DNA

Researchers at TU Delft working with colleagues at Oxford University have announced the development of a new type of nanopore device that could help in developing faster and lower-cost gene sequencers.

The method combines a man-made and biological nanopore on a chip, which is able to measure and analyse single DNA molecules.

Nanopores can be used to determine the identity of a DNA base as its threads through the hole. An Oxford University spin-out, Oxford Nanopore, has been set up to commercialise this technology.

Now, new research by Cees Dekker’s group at TU Delft in collaboration with Hagan Bayley of Oxford University, has demonstrated a new, much more robust type of nanopore device, which combines biological and artificial building blocks.

Dekker said, “Nanopores are already used for DNA analysis by inserting naturally occurring, pore-forming proteins into a liquid-like membrane made of lipids. DNA molecules can be pulled individually through the pore by applying an electrical voltage across it, and analysed in much the same way that music is read from an old cassette tape as it is threaded through a player.”

One aspect that makes this technology especially difficult, however, is the reliance on a fragile lipid support layer. This new hybrid approach is much more robust and suited for integrate nanopores into devices.

In the new method, an individual protein is attached to a larger piece of DNA, which is then pulled through a pre-made opening in a silicon nitride membrane. When the DNA molecule threads through the hole, it pulls the pore-forming protein behind it, eventually lodging it in the opening and creating a strong, chip-based system that is tailor-made for arrays and device applications.

The researchers have shown that the hybrid device is fully functional and can be used to detect DNA molecules.