The MinION(TM) is a miniature nanopore-based analysis device in which the characteristics of an analyte, as it passes through the nanopore, cause changes in the flow of ions through the pore, which are measured, as current flow, by a low noise amplifier and analogue-to-digital converter. Potentially any molecular analyte capable of passing through the nanopore may modify the flow of ions and generate a signal which might be diagnostic. In practice the current device is focussed on DNA sequencing, directly sequencing RNA is a likely development. With the MinION Access Program making the MinION(TM) widely available a flood of applications exploiting its real time, long read capabilities have been published. We review the background to the technology and compare it to current next generation sequencing.