Open Minion nanopore sequencer, a device designed to determine the order in which nucleotides occur on a strand of DNA (deoxyribonucleic acid). A nanopore is a hole in a membrane with a diameter of around 1 nanometre. When a nanopore is immersed in a conducting fluid and a voltage is applied across it, ions are conducted through it creating a current. When a strand of DNA passes through the nanopore, each nucleotide obstructs the nanopore to a different, characteristic degree, creating a characteristic change in the current. The current changes represent a direct reading of the DNA sequence.