Though the development of sequencing changed the field of microbiology, older techniques have proven to be painstakingly slow, as bacterial genomes consist of several million base pairs (not to mention the human genome, which is made up of 3.2 billion). While working on his doctorate 20 years ago, UVA associate professor of biology Martin Wu recalls only being able to collect 300 base pairs in a day.
Flash forward two decades, and Wu is now teaching a group of undergraduate students how to sequence hundreds of thousands of base pairs in a matter of seconds.
Titled “NextGen Sequencing: Minions the Microbe Detective,” his course utilizes MinIONs, an Oxford Nanopore Technology. At the size of a thumb drive, the device contains hundreds of parallel pores with dimensions of only a few nanometers. In essence, each MinION contains one membrane that acts like a barrier, and when proteins are placed into this membrane, they act as channels, allowing DNA base pairs to pass through. The four base pairs of DNA – adenine, cytosine, guanine and thymine – are different shapes and sizes, blocking the electric current in different ways. When the MinION picks up on the different signature changes in current, it is able to sequence each DNA fragment in real time.