Genome Sequencing Recently I looked at how graphene might be used to sequence DNA – here’s another recent advance that uses one protein to chop up DNA, followed by another that acts as a nanoscale sized hole in a membrane, allowing the individual identification of bases (the A, C, G and T’s that make up a genome).
The membrane, made out of the same stuff that makes the cell wall, acts to separate two solutions one of which contains the DNA. When a voltage is applied across the membrane, charged molecules including the DNA want to pass to the other side of the reservoir but are stopped from doing this by the membrane.
The proteins form a small hole in the membrane that allows ions to pass through, however when the DNA tries to get through it is chopped up so each base passes through separately. Each base blocks the hole to a different extent, meaning there is a change in current of ions and the base can be identified.