The present application claims priority of European Application No. EP 20 156 954.8 filed on Feb. 12, 2020. The aforementioned application is hereby incorporated by reference in its entirety.
The invention relates to a device and a method for the extraction of nucleic acids from samples comprising cells.
Automated analyzer systems for use in clinical diagnostics and life sciences are produced by several companies. For example, STRATEC® SE, Birkenfeld, Germany, produces a number of devices for specimen handling and analysis of samples, including diagnostic applications, for use in automated analyser systems and other laboratory instrumentation.
Nucleic acid extraction (NAE) methods relate to the extraction of both DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) from samples but can be more broadly separated into chemical and mechanical methods. The following descriptions will focus on mechanical solid-phase methods and furthermore address processes which are based on magnetic particles or beads.
The magnetic beads technology represents a well-established strategy for the extraction of RNA and genomic, plasmid and mitochondrial DNA. Suitable buffer systems (mainly silica matrices) will be coupled via coating procedures to functionalized magnetic particles or beads. The extraction technique involves the separation of nucleic acids from complex mixtures and provides several advantages compared to other isolation processes:
In general, all semi-automated and fully automated NA extraction systems/instruments perform the following basic process steps of:
Considering these basic steps in combination with the magnetic particle/bead approach all system-specific NA isolations come down to the four steps of lysis, binding, washing and elution. The modules or stand-alone instruments mainly differ in the actual implementation of the basic process steps.
A traditional extraction protocol, which employs magnetic beads (MBs) to isolate nucleic acids from whole blood in a disposable tube or vessel comprises the following steps:
U.S. Pat. No. 8,454,825 teaches a rod assembly for the extraction of magnetizable particles from solutions. The rod assembly includes at least one guide element. A rod element that is insertable into the at least one guide element and moveable in a direction substantially parallel to the at least one guide element. A magnet element is moveable to a distal magnet element position; wherein the distal magnet element position is located on a distal end section of the at least one guide element; wherein the at least one guide element includes an opening at a distal end. A method for the extraction of magnetizable particles from solutions is also described, as well as a magnet element for the extraction of magnetizable particles from solutions.
Other systems known from the prior art transfer the liquids between reaction wells via disposable tips and separate the magnetic beads (w/o bound NA) inside the cavities. The processing principle includes the following steps:
Another alternative is to transfer the liquids between reaction wells via disposable tips, wherein the magnetic particles (w/o bound NA) are separated inside the tip. The processing principle includes of the following steps: 1. Introduce sample to the instrument. 2. Cell disruption and protein digestion by addition of lysis buffer and enzyme. 3. NA binding to the surface of magnetic particles. 4. Magnetic separation of the nucleic acid-bead complex. 5. Removal of cellular debris by extensive washing steps. 6. Magnetic separation of the nucleic acid-bead complex. 7. NA elution at high temperatures during the removal of the magnetic particles.
There is also a system known, which performs the extraction in a single reaction cavity. The magnetic particles will be manipulated (separation and resuspension) via multiple movable magnetic arrays. Injectors dispense reagents and by the use of disposable aspirator tips the supernatant from each well can be removed. The processing principle includes the following steps: 1. During incubation of the lysed samples, all target nucleic acids are captured by magnetic particles. 2. The magnetic device attracts all magnetic beads, enabling the system to purify nucleic acids through several washing steps. 3. The heating step releases the NA form the beads. 4. At the final step, magnetic particles are separated from the eluate by the magnetic device.
All systems known from the prior art are related to a limited flexibility with respect to liquid components and assay extraction parameters.
It is therefore the object of this invention to provide a device and a method for the extraction of nucleic acids from a cell sample with a high degree of flexibility regarding the used liquids and assay parameters.
The present invention provides a consumable for handling liquids in automated analyser systems, comprising:
In a further aspect of the present invention, the bridge can have a concave shape between two neighbouring cavities of the plurality of cavities to collect spilled liquids.
In another embodiment, the bridge can be arranged next to the openings of the plurality of cavities.
It is further intended for a consumable of the present invention, that each of the plurality of cavities may have a different diameter and/or depth and/or shape.
Another object of the present invention relates to a device for processing samples in an automated analyser system, comprising:
In a further aspect of the present invention, the device may comprise sections for different processing steps which are each stored in the control unit for performing them,
Another embodiment of the device may further encompass a further section which is configured to accommodate a plurality of consumables which can be processed simultaneously.
It is also intended that the device of the present invention may further comprise means for transporting the consumables between different sections.
It is also envisaged that a device of the present invention may comprise means for transporting of the consumable comprising a sledge with a corresponding drive system.
In a further embodiment of the present invention, the sledge may comprise cavities for heating and/or cooling of liquids in a cavity of the plurality of cavities in a consumable and/or magnets for separating magnetic beads comprised in a liquid in a cavity of the plurality of cavities in a consumable.
It is also intended that a device of the present invention may comprise a section for nucleic acid isolation and/or for performing Polymerase Chain Reactions.
The dispense robot of a device according to the present invention may further comprise a plurality of dispense units.
The present invention relates further to a method for extraction of a target compound from a liquid, comprising the steps of:
In a further aspect of the present invention, the target compound can be a nucleic acid, peptide or protein.
The method of the present invention may further comprise a step wherein the separation magnets can be moved along the outer wall of the target cavity.
It is further possible that the predefined protocol comprises the step of cooling of the liquids.
Another object of the present invention is the use of a method as described above for the extraction of nucleic acids in a first section of a device as described above and for performing Polymerase Chain Reactions in a neighbouring section of said device.
Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, simply by illustrating preferable embodiments and implementations. The present invention is also capable of other and different embodiments and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description or may be learned by practice of the invention.
The invention will be described based on figures. It will be understood that the embodiments and aspects of the invention described in the figures are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects of other embodiments of the invention, in which:
The technical problem is solved by the independent claims. The dependent claims cover further specific embodiments of the invention.
The invention refers to a part of a fully automated analysis system in the field of molecular diagnostics, which can perform nucleic acid extraction (NAE) as well as polymerase chain reaction (PCR) with a complete sample to result workflow (instrument shown in
The consumable 1 according to the present invention, which is used for nucleic acid extraction, is a multi-cavity reaction disposable and provides different vessels for lysis 5, washing 9, elution 11 as well as the intermediate storage/holding of liquid waste and disposable tips 2 (
An integrated interface 7, 8 allows the automated handling and transport of the consumable 1 by a handling device like an internal robotic device (gripper) of the instrument (
All cavities are arranged in a single line in order to reduce the required processing/handling effort. Small drip pans/chambers 15 between the reaction-wells collect dropped and spilled liquids for avoiding the unintentional spread of the fluids. To prevent potential contamination of the gripper, the handling/gripping interface 7 is located on one side besides the cavity array.
One receptacle serves as a tip stand 2 for holding and a possibly required intermediate storage/parking of disposable tips 19. The consumable will be equipped during extraction with a tip by a handling device like a pipetting robot 17 (
The embodiment of an extraction module, which is described below for illustrating the invention, uses this tip for different liquid handling steps. After finishing nucleic acid isolation, disposable tips 19 can be stored back to the tip stand 2 for final disposal (
As already mentioned, an embodiment of an instrument for NAE and PCR is illustrated in
The mentioned module consists of four discrete and full-featured isolation bays which are able to perform all required process steps from lysis to elution excluding the addition of liquids. In the shown configuration all isolation bays share one dispense robot (called dispense sledge) 44, which is an integral part of the extraction module 34. In combination with the former mentioned liquid supply system the dispense sledge 44 is responsible for the injection of bulk fluids where the tip-based pipetting robot adds special/sensitive reagents and sample.
The isolation bays are designed as batch systems for the simultaneous processing of up to four samples and consumables, respectively. The batch sizes can be adapted according to the technical and commercial requirements/needs of the instrument. All these devices are equipped with the same functionalities (hardware). As a result of that the partial redundant extraction system provides a high flexibility regarding the detailed planning and execution of assay workflows (e.g., repetition of single steps, individual process times/durations etc.) up to the processing of different extraction protocols at the same time. The according module is shown in
Each isolation bay is mainly composed of a consumable transport 50, a wash lift/tower 52 and an air pump-based pipetting module. The transport device moves the consumables between the different working positions (e.g., consumable loading and unloading, disposable tip pick-up and set down etc.). It includes a sledge 50 with corresponding drive system, integrated cavity heating 54 for lysis and elution as well as the magnetic particle separation devices 56 (e.g., permanent magnets). Every sledge 50 can also provide optional tip stand interfaces for the handover of tips to the extraction module by the pipetting robot and vice versa (if necessary).
The wash lift 52 (automated Z-axis) and the air pump pipetting module carry out essential liquid handling steps of the extraction. All these processes are tip-based and will be listed below:
According to this principle, each lift is able to pick up multiple disposable tips 19 (up to four) at the same time from the extraction consumables 1 or from the transport sledge directly. For that, the lift sledges provide dedicated tip interfaces. The NA isolation of subsequent/other samples requires that all devices can place the contaminated tips back to the corresponding extraction consumable 1 or the optional positions of the transport sledge. In addition, every lift assembly is equipped with four aspiration probes 60 for the discarding of liquid waste (e.g., supernatant or used reagents). The individual probes are connected via flexible tubing with a pump system to transfer the liquid waste to the relating reservoirs/containers.
The dispense robot (sledge) 44, which is operating above the consumable insertion positions of the extraction part 34, injects diverse bulk fluids into the individual reaction vessels according to the assay workflow. The robot is able to reach all consumable locations for the sequential and demand-based reagent dispense. Every sledge will be supplied by a fluidic/pump system that transfers the liquids from the storage container(s)/reservoir(s) to the individual injection ports. The robotic device can be equipped with two or more dispense units to generate also a redundant subsystem.
After completion of the final elution step (addition of elution buffer) the transport sledge of each isolation bay moves the extraction consumable(s) 1 containing the processed sample(s) to the according insertion and remove position. The handling robot will pick up the consumables 1 and transport them to a so-called eluate shuttle 46 (
The principal operation method and the available system functionalities, which were outlined above, will be explained in detail based on an exemplary extraction process step description in table 1. All assay parameters, for example, processing orders, volumes, temperatures, repetition numbers, durations etc. are adaptable, but the functional principle remains unchanged.
The advantages of the invention can be summarized as follows:
Alternative approaches may encompass:
The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. The entirety of each of the aforementioned documents is incorporated by reference herein.
Number | Date | Country | Kind |
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20156954.8 | Dec 2020 | EP | regional |