Quantum Biosystems

Quantum Biosystems was a Japanese company that tried to read DNA by passing a strand between two electrodes less than a nanometer apart and measuring the electron current that tunnels across the gap. It grew out of work at Osaka University, was founded in 2013 and, in the words of the university, "concluded its activities in 2023".^[1] It appears in the List of nanopore companies although its method used no pore.

A nanopore sequencer reads the ions that flow through a hole. Tunneling sequencing reads electrons. Two electrodes are held so close that electrons can cross the gap between them with no wire joining them, and the size of the current depends on what sits in the gap. A single nucleotide in the gap changes the current, and different nucleotides change it differently.^[2] The 2012 paper stated the aim as label-free sequencing that needs no amplification by PCR.^[3]

The idea began as theory, and the theory had a pore in it. A paper of 2005 reported calculations of charge transport across a single strand, perpendicular to its backbone, and found that with electrodes of the right width each of the four nucleotides carries a unique signature.^[4] A second, in 2006, proposed measuring those transverse currents while a strand translocates through a nanopore, and estimated that a human genome could be sequenced in hours.^[5]

In 2010 a group at Osaka University's Institute of Scientific and Industrial Research reported the electrical detection of single nucleotides with two configurable nanoelectrodes. They showed that electron transport through single nucleotides occurs by tunneling, and that the nucleotides can be identified statistically from their electrical conductivity.^[2] An abstract by the group in 2015 describes its measurements with a nanofabricated mechanically controllable break junction, a metal bridge that is bent until it breaks, after which further bending sets the width of the gap.^[6]

In 2012 the group combined the method with a sequencing strategy. Single bases were identified by their tunneling currents and read at random from fragments, and the paper read nine types of DNA oligomers. It also identified the sequence 5'-UGAGGUA-3' of the let-7 family of microRNA by combining overlapping fragment sequences, each determined from the tunneling current of single bases passing between a pair of nanoelectrodes.^[3] A paper of 2014 from the same group detected post-translational modifications in single peptides by their tunneling currents.^[7]

Quantum Biosystems Co., Ltd. was founded in 2013 as a venture of the Osaka laboratory. The university's page on its startups describes it as "a device for reading DNA information using nanotechnology", with research bases in Osaka and in Silicon Valley, and says that it concluded its activities in 2023.^[1] The page names no product. The same page lists a second Osaka venture, Aipore, founded in 2018, which pairs solid-state nanopores with machine learning, and records that it concluded its activities in 2025.^[1]

The sequencing paper of 2012 read oligomers of a few bases and a seven-base fragment of RNA.^[3]

Molecular Reality Corporation also sets the size of an opening mechanically. In its design, called sliding occlusion, one membrane slides over another to change the opening of a pore; a Signal & Noise article of October 2026 on the idea notes that the design is not yet a sequencer.^[8] The Osaka group set its electrode spacing mechanically as well, by bending a break junction.^[6]

• List of nanopore companies
• Mechanical nanopore
• Roswell Biotechnologies
• Single-molecule biophysics