Sequencing on a Snap In Cartridge Etched Channels, Squeezable Adapters and Parallel Readout

This application covers a complete DNA sequencing system built around a cheaper kind of flow cell. The claimed system pairs a microfluidic chip carrying at least two etched channels with compressible polymer end fittings, mounts the whole thing in a cartridge that the channels seal into when they mate with those fittings, and reads the channels with a fluorescence imaging module feeding a computer that processes the resulting data in parallel. It was filed by Element Biosciences, Inc., the San Diego company behind the AVITI sequencing platform, and it is the second Australian divisional in a family that began with a US provisional application in December 2018.

The Problem

A flow cell is the consumable at the heart of a sequencing run. It holds template nucleic acid molecules immobilised on an internal surface, then takes a repetitive flow of reagents that attach labelled nucleotides to positions along those templates. A camera reads the label signals cycle by cycle, and the sequence is decoded from the series.

The complaint is about how those parts are made. The specification describes typical next generation sequencing flow cells as multi layer structures fabricated from planar substrates and other components, bonded mechanically, chemically or by laser to form the fluid channels, a construction that requires costly multi step precision fabrication to reach the required specifications. Since the flow cell is consumed on every run, that cost passes straight through to the price of sequencing.

The obvious cheap alternative does not work as it stands. Single lumen capillaries are available off the shelf in many sizes and shapes and cost very little, but the specification objects that they are not suited to ease of handling and not compatible with the repetitive switching between reagents that sequencing requires. A bare glass tube has no reliable way to seal to an instrument’s fluid lines and be swapped out between runs.

Reagent consumption is the third cost. The specification frames its own design as achieving more efficient use of expensive reagents and cutting the time needed for sample pretreatment, which is the same economics from the other direction: not just what the consumable costs to build, but how much chemistry gets flushed through it.

What This Invention Does

Claim 1 is a system claim for identifying a nucleic acid sequence, and it has four parts.

The first is the flow cell. It comprises a microfluidic chip with at least two microfluidic channels, where the surface of a channel is configured to immobilise a nucleic acid molecule and the interior surface of each channel comprises a patterned etched layer. A first fluidic adapter sits at the distal end of each channel and a second at the proximal end, both formed of a polymeric material and both fluidically connected to each channel, to a sample input port, or to a reservoir. A cartridge holds the channels and both adapters, the adapters are compressible, and each channel is mounted in the cartridge upon mating with them. That last limitation is the mechanical core of the claim: the seal and the mounting are the same act, and the squeeze of a soft polymer fitting does both.

The second part is the reservoir, in fluid communication with the channels and holding a fluorescent detection reagent for a sequencing reaction. The third is a fluorescence imaging module configured to acquire an image of the surface of each channel, so as to obtain a signal from labelled nucleic acid molecules in each one.

The fourth part is the computing. Claim 1 requires a computer system comprising a programmable logic circuit programmed to process in parallel the sequencing data generated from the two or more fluorescent signals, in order to determine the sequence. Dependent claim 13 narrows that circuit to a field programmable gate array, and a later claim covers doing the parallel processing on a cloud computing device instead. The claim therefore ties the multi channel flow cell to a readout that handles the channels concurrently rather than in sequence, which is what makes adding channels useful.

Elsewhere the specification has the etched layer bonded to one or two non etched layers forming the cover or floor of the channels, adapters made from materials including silicone or a fluoroelastomer where compressibility is wanted, and adapter attachment by press fit, adhesive bonding, solvent bonding or laser welding. That last method is why the application also carries a plastics welding classification alongside its laboratory apparatus one.

Key Features

• Etched channels rather than bonded planar layers. The channels are formed by patterning an etched layer in a chip, which the specification presents as a shorter and less expensive route than the multi step precision bonding used in conventional flow cells.
• Compressible polymer end fittings. The adapters are soft enough to seal under compression, so a channel is sealed and located in the cartridge in one movement.
• Mounting by mating. Claim 1 requires each channel to be mounted in the cartridge upon mating with the two adapters, which is what makes the assembly serviceable and the channels replaceable.
• At least two channels, read together. The claim requires two or more channels and requires the fluorescent signals from them to be processed in parallel, so throughput scales with channel count instead of run time.
• Programmable logic in the claim. The data path is claimed as a programmable logic circuit, narrowed in a dependent claim to a field programmable gate array and elsewhere to cloud processing.
• Optically transparent windows. The specification allows the whole chip or capillary to be transparent, or only a defined window, which is what the fluorescence imaging module looks through.

Who Is Behind It

The applicant is Element Biosciences, Inc., founded in San Diego in 2017 by three scientists who had previously worked at Illumina. Its AVITI benchtop sequencer launched in 2022 and is positioned against mid throughput instruments from Illumina, the company that has dominated short read sequencing for most of the last two decades.

Five inventors are named: Minghao Guo, Leon Zilun Zhang, Chunhong Zhou, Matthew Kellinger and Michael Previte. Two of them are among the company’s founders: Previte, who is chief technology officer, and Kellinger, who leads biochemistry. That the founding technical leadership is on a flow cell patent rather than a chemistry one is a fair signal of how central the consumable is to the company’s cost argument.

The chain is three deep. AU 2026202136 is a divisional of Australian application 2024200383, itself a divisional of 2019392932, which was the Australian national phase of PCT/US2019/065073, filed 6 December 2019 and published as WO 2020/118255. That international application claims the benefit of two US provisional applications, 62/776,827 filed 7 December 2018 and 62/892,419 filed 27 August 2019, which makes the United States the priority country. The corresponding US patent, US 11,426,732, issued in August 2022.

Why It Matters

Sequencing economics are consumable economics. Instrument prices attract the headlines, but a laboratory running samples continuously spends far more over a few years on flow cells and reagents than on the machine, which is why every serious entrant to massively parallel sequencing has had to attack the consumable stack rather than just the box. A flow cell built with fewer precision bonding steps, sealing to the instrument through a compressible fitting instead of a permanently mated interface, is a direct move on that cost.

Element launched AVITI into a market where the incumbent’s sequencing by synthesis chemistry and its patent estate had both been obstacles to challengers for years, and the company has been explicit about targeting laboratories that want an alternative at a moderate price. The off the shelf capillary option, the interchangeable cartridge and the parallel readout path all read as an attempt to build a consumable that is cheap to manufacture without giving up the imaging quality the chemistry needs.

Filing a second Australian divisional in 2026, more than seven years after the priority date, is a portfolio decision rather than a product one. Australia is not a large sequencing market by revenue, but it hosts substantial genomics research capacity and national genome sequencing programmes, and divisionals let an applicant keep pursuing claim scope in a jurisdiction while a parent is examined or lapses. The claim set here reaches beyond the flow cell itself to the imaging and data processing around it, which is a broader position than the title suggests and a harder one to design around.

Related Concepts

• Massively parallel sequencing – the sequencing approach whose consumable economics this design targets.
• Fluorescence microscopy – the imaging principle behind the module that reads each channel.
• Lab on a chip – the broader category of miniaturised fluidic devices this flow cell is an instance of.
• Laser beam welding – one of the adapter attachment methods, and the reason for the plastics welding classification on the file.
• Field programmable gate array – the named form of the programmable logic circuit that processes the channels in parallel.

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AU 2026202136 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.