A lid assembly for a sample tube, a method for collecting magnetic beads using it, and a sample processing kit.

Abstract

A lid assembly for a sample tube for collecting magnetic beads from the sample tube and subsequently releasing the beads, the lid assembly comprising: a closure portion including means for removably attaching the closure portion to an opening of the sample tube to close the sample tube; a bead collection platform configured to be positioned within or above the opening of the sample tube when the closure portion is attached to the sample tube, the bead collection platform having a bead collection surface on one side for contacting liquid in the sample tube during use and a magnet storage cavity on the other side behind the bead collection surface; and a magnet holder portion comprising a magnet, the magnet being removably insertable into the magnet storage cavity toward the bead collection surface such that when the magnet is present in the magnet storage cavity, the magnet can hold the magnetic beads against the bead collection surface and when the magnet is not present in the magnet storage cavity, the lid assembly is unable to magnetically hold the magnetic beads against the bead collection surface. Methods of using such devices to collect magnetic beads from liquids in sample tubes, as well as related kits and accessories, are also provided.

Description

TECHNICAL FIELD

[0001] This invention was made with United States Government support under grant number R01AI128765 awarded by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health. The United States Government has certain rights in this invention.

[0002] The present invention relates to a lid assembly for a sample tube adapted to collect magnetic beads from liquid within a sample tube, and to related methods of using such an apparatus. The apparatus and methods are particularly, but not by any means limited to, suitable for performing extraction of target biomolecules from solid or liquid samples using magnetic separation. A sample processing kit including such an apparatus is also provided along with several accessories.

[0003] As used herein, the term "magnetic beads" is to be broadly interpreted. First, the term "magnetic" should be broadly interpreted to include "paramagnetic". Furthermore, the term "beads" should also be broadly interpreted to encompass particles of various sizes including nanoparticles (i.e., particles having a diameter of less than 1 µm), micron-sized particles (i.e., those having a diameter of about 1 to 500 µm), and larger particles (in some cases up to about 1 mm in diameter). As those skilled in the art will appreciate, the principles of the present disclosure are not limited to any particular size or composition of magnetic "beads", and it will be understood that for any given application, those skilled in the art will use beads of appropriate size and composition. BACKGROUND ART

[0004] Magnetic separation using magnetic beads is an established technique for extracting target biomolecules from a sample.

[0005] Magnetic beads typically consist of two components: a magnetic material (often iron, nickel, or cobalt) and a chemical component that provides functionality to the beads, thereby allowing them to adhere to biomolecules or other chemical or biological species. Such species may include, but are not limited to, polynucleotides such as nucleic acids (e.g., RNA or DNA), proteins, biological cells, and other chemical or biological molecules.

[0006] The principle of magnetic bead extraction is well established and outlined in, for example, U.S. Patent No. 4,554,088 and U.S. Patent No. 5,705,628, which themselves refer to further background art relating to this art.

[0007] More recently, U.S. Patent Application Publication 2015 / 0196905A1 proposes a centrifugal liquid container with a magnet integrated into its lid for separating magnetic beads in a suspension in a liquid, comprising four removable components: a centrifugal liquid container, a small removable magnet, a hollow cylindrical connector cap, and an open lid adapter. During use, the components are attached together by screw threads.

[0008] The fact that the container described in U.S. Patent Application Publication 2015 / 0196905A1 is specifically centrifugally centrifugable suggests that, in practice, centrifugation may often be necessary to fully perform its intended function. However, the use of a centrifuge limits the use of the container to a laboratory or at least a location where electricity is available. This makes the container unsuitable for use in locations without a power source or where the use of a centrifuge is impossible.

[0009] Another potential drawback of the apparatus disclosed in U.S. Patent Application Publication No. 2015 / 0196905A1 is that the use of threads between components may make the apparatus somewhat cumbersome and time-consuming to use. Indeed, the components do not appear to be conducive to quick and easy use, which increases the risk of contamination of the magnetic beads, particularly when transferring them between containers. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent No. 4,554,088 [Patent Document 2] U.S. Patent No. 5,705,628 [Patent Document 3] U.S. Patent Application Publication No. 2015 / 0196905A1 [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, there is a need for a device that addresses at least some of the above problems in order to enable a rapid, simple, low-cost, and powerless extraction process for target biomolecules from samples using magnetic beads. [Means for solving the problem]

[0012] According to a first aspect of the present invention, a lid assembly as described in claim 1 of the appended claims is provided.

[0013] Accordingly, a lid assembly for a sample tube is provided for collecting magnetic beads from a sample tube and subsequently releasing the beads, the lid assembly comprising: a closure, means for closing the sample tube by removably attaching the closure to the opening of the sample tube; a bead collection platform configured to be positioned inside or above the opening of the sample tube when the closure is attached to the sample tube, having a bead collection surface on one side for contact with the liquid inside the sample tube during use, and a magnet housing cavity on the opposite side behind the bead collection surface; and a magnet holder, comprising a magnet, wherein when the magnet is in the magnet housing cavity, the magnet can hold magnetic beads relative to the bead collection surface, and when the magnet is not in the magnet housing cavity, the lid assembly is removably insertable into the magnet housing cavity toward the bead collection surface such that the magnet can hold magnetic beads relative to the bead collection surface.

[0014] As those skilled in the art will understand from this disclosure, the term “sample tube” as used herein should be broadly interpreted to encompass any suitable tube that may be used to contain or process a sample or derivative of a sample.

[0015] Because the magnets are removablely insertable into the magnet housing cavity, the state of the lid assembly can be quickly and easily changed from a state where the magnetic beads are attracted to the bead collection surface to a state where such beads are released, without requiring the use of electricity. This also helps the device to be used effectively in remote locations without requiring expert training.

[0016] Furthermore, as described herein, being platform-shaped, the bead collection platform advantageously allows the collected magnetic beads to be held substantially exposed to ambient air when the lid assembly is removed from the sample tube, thus aiding in the drying of the collected beads during use.

[0017] In a presently preferred embodiment, the magnet holder is completely separable from the closure, which makes the device easy to use, simple and inexpensive to manufacture, and thus readily available to end users.

[0018] However, in other variants, the magnet holder may be coupled to the closure, and the magnet is movable within the magnet receiving cavity toward or away from the bead collection surface.

[0019] Preferably, the magnet holder further comprises a user grippable portion to which the magnet is attached, which makes it easy for a user to operatively insert the magnet into the magnet receiving cavity and subsequently remove the magnet from the magnet receiving cavity.

[0020] The user grippable portion may have a relatively thin and flat shape, and can be easily gripped between a user's thumb and index finger. Alternatively, the user grippable portion may have a cross-sectional profile that allows it to function as a stand for supporting the magnet holder upside down, optionally with the closure and the sample tube attached thereto. The magnet receiving cavity may be in the form of a socket shaped to receive at least the magnet of the magnet holder. Optionally, the magnet holder may be rotatable within the socket.

[0021] In certain embodiments, the magnet holder and the closure may be mutually engageable when the magnet is inserted into the magnet receiving cavity. Accordingly, the magnet may be reversibly locked in place within the magnet receiving cavity, thereby reliably maintaining the bead attraction state of the lid assembly and preventing accidental dropping of the magnet holder. This may be particularly beneficial when inverting the sample tube with the lid assembly attached, or when using the lid assembly to transport magnetic beads from one sample tube to another.

[0022] For example, the magnet holder may optionally comprise one or more radially protruding portions, and the socket may comprise one or more complementary channels with which the one or more radially protruding portions are engageable. Alternatively, the magnet holder and the socket may comprise threads engageable with each other. Alternatively or additionally, the socket may comprise gripping means (e.g., a protrusion or a ridge) for gripping the magnet holder.

[0023] Advantageously, for quick and easy use, the means for removably attaching the closure to the opening of the sample tube may comprise a press-fit portion adapted to engage with the opening of the sample tube. In a currently preferred embodiment, the press-fit portion is a bead collection platform. In an alternative embodiment, the means for removably attaching the closure to the opening of the sample tube may comprise a snap-fit mechanism.

[0024] In various embodiments, the closure may have an elongated shape, as it has been found to work well in combination with sample tubes having a hinged cap when viewed from above.

[0025] The closure may be provided with first and second finger tabs (optionally having recessed or textured outer surfaces) on both sides of the closure so that a user can grip the closure with the user's thumb and fingers during use.

[0026] In specific embodiments, the first and second finger tabs extend below the bead collection surface and can function as a stand for supporting the lid assembly in an upright orientation when separated from the closure.

[0027] Alternatively or additionally, the first and second finger tabs may extend above the bead collection surface and can function as a stand for supporting the lid assembly (optionally with a sample tube attached) in an inverted orientation.

[0028] The bead collection platform may extend parallel to the first and second finger tabs and be separated from them. In particular, such a configuration promotes airflow around the bead collection platform when the lid assembly is removed from the sample tube, thus promoting the drying of any magnetic beads collected thereon (such beads are substantially exposed to the air), while protecting the bead collection surface from accidental contact by the user's fingers.

[0029] Optionally, the bead collection surface may incorporate concave or recessed areas to facilitate the collection of magnetic beads. Alternatively, the bead collection surface may be convex to help the collected magnetic beads dry.

[0030] Alternatively, or additionally, the bead collection surface may incorporate an array of indentations or recesses to promote a uniform distribution of magnetic beads across the bead collection surface. Optionally, the bead collection surface may incorporate a fluid wicking component (e.g., a wicking spike) to facilitate the removal of liquid from the bead collection surface.

[0031] A second aspect of the present invention provides a kit comprising a lid assembly according to the first aspect of the present invention, at least a first sample tube, and optionally a pipette and / or a swab and / or a further sample collection tube.

[0032] In one embodiment, the kit may have multiple sample tubes connected side by side to facilitate the use of the tubes in the required order. Optionally, the last sample tube may be connected to its adjacent sample tubes by a fragile connection to allow for subsequent processing of the contents of the last tube, separated from the other tubes.

[0033] In certain embodiments, the kit may have first, second, and third sample tubes. For example, the first sample tube may contain a dissolution / binding buffer, the second sample tube may contain a washing solution, and the third sample tube may contain an eluent. The tubes in the kit may be pre-filled with such liquids. Additionally or alternatively, the first sample tube may be pre-filled with magnetic beads. However, alternatively, the magnetic beads may be provided in a separate container, sachet, blister pack, mold-filled tube, etc.

[0034] Advantageously, the packaging for the kit (including sample tubes, lid assemblies, and optionally other components) may be configured to function as a stand / station for the kit contents during use, thereby replacing additional laboratory equipment such as tube racks. More specifically, the kit may comprise a tray incorporating one or more recesses or cavities for supporting the sample tubes, and a recess in which the lid assembly is placed. Thus, the packaging can provide a dedicated area for arranging each tube during processing steps and a dedicated space for arranging the lid assembly to allow liquid to evaporate from the magnetic beads held on the bead collection surface. The packaging can also provide a dedicated space in which the sample collection / swab tube can remain during the extraction procedure, thus effectively linking the sample with the extraction kit. The packaging may also include a cover that, once used, can function as a waste container for the sample tubes and other contents of the kit, or as a temporary intermediate preparation area.

[0035] According to a third aspect of the present invention, a sample tube is provided having a resealable cap, the cap comprising a compartment for containing a reagent, the compartment having a removable cover for sealing the reagent therein. In particular, the compartment may be located inside the cap such that the compartment is located inside the sample tube when the cap closes the sample tube. This cap compartment facilitates the introduction of a predetermined amount of a predetermined reagent into the liquid in the sample tube. The reagent may be wet and / or lyophilized and may be used, for example, for amplification, detection, or biosensing of an extracted analyte present in the liquid in the sample tube. The cap may be attached to the tube by a flexible hinge.

[0036] In some embodiments, the reagent may be in the form of beads, which facilitates loading the reagent into the compartment and allows the entire reagent to be delivered as a single unit, for example, by dropping it from the compartment into the tube. However, in other embodiments, the beads may be press-fitted into the compartment to prevent them from accidentally falling out.

[0037] In certain embodiments, the reagent may be a lyophilized colorimetric detection reagent. As will be understood by those skilled in the art, in other embodiments, the reagent may be lyophilized and not colorimetric, and in yet another embodiment, the reagent may not be lyophilized and not colorimetric. Therefore, more generally, the reagent can be any suitable detection reagent.

[0038] The kit of the second embodiment described above may include at least one sample tube according to the third embodiment in order to function in particular as the third sample tube described above. According to a fourth aspect of the present invention, a method for collecting magnetic beads from a liquid in a sample tube (in which beads can be suspended in the liquid), wherein the method is The steps include attaching the closing part of the lid assembly described above to the opening of the sample tube, The method comprises the steps of agitating (e.g., gently shaking or inverting) a liquid with a magnet inserted into a magnet housing cavity such that the magnetic beads come into contact with the bead collection surface and are held in place by the magnet. Such a process is quick and easy to perform and does not require the use of electricity, centrifuges, or specialized training. The sample tube may be a first sample tube containing a first liquid, and this method is With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the first sample tube. The steps include attaching the closing portion of the lid assembly to the opening of the second sample tube containing the second liquid, The method comprises the step of removing the magnet from the magnet housing cavity such that the magnetic beads are no longer held in place by the magnet against the bead collection surface and are suspended in a second liquid.

[0039] Therefore, this allows the lid assembly to quickly and easily transfer the magnetic beads from the first liquid in the first sample tube to the second liquid in the second sample tube. Furthermore, in order to transport the beads further, this method The steps include: reinserting the magnet into the magnet housing cavity (while the closing portion of the lid assembly is still attached to the opening of the second sample tube), The steps include stirring the second liquid so that the magnetic beads come into contact with the bead collection surface and are held in place by the magnets relative to the bead collection surface, With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the second sample tube. The steps include attaching the closing portion of the lid assembly to the opening of the third sample tube containing the third liquid, The method comprises the step of removing the magnet from the magnet housing cavity such that the magnetic beads are no longer held in place by the magnet against the bead collection surface and are suspended in a third liquid. To optionally remove the magnetic beads from the third liquid, this method allows for the final removal of the magnetic beads from the third liquid. The steps include: reinserting the magnet into the magnet housing cavity (while the closing portion of the lid assembly is still attached to the opening of the third sample tube), The third step is to agitate the liquid so that the magnetic beads come into contact with the bead collection surface and are held in place by the magnets relative to the bead collection surface. With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the third sample tube. The next step is to optionally place the lid assembly and / or magnetic beads.

[0040] In certain practical embodiments, the method may be for the extraction of a target biomolecule (e.g., characteristic nucleic acids of a particular virus (e.g., RNA or DNA) - e.g., SARS-CoV-2, but not limited to this), where, The first liquid is a dissolution / binding buffer for dissolving target biomolecules, thereby releasing them into the solution and binding the biomolecules to magnetic beads. The second liquid is a cleaning solution. The third liquid is an eluent used to dissolve biomolecules. Therefore, the target biomolecule may include nucleic acids.

[0041] This method may further include the steps of introducing a detection reagent (e.g., a colorimetric detection reagent) into the eluate and, if necessary, applying heat to determine the presence or absence of the target biomolecule.

[0042] The third sample tube (containing the eluate) may be the sample tube according to the third embodiment described above, the reagent held in the cap compartment is a detection reagent, and the step of introducing the detection reagent into the eluate comprises the step of releasing it from the cap compartment of the sample tube.

[0043] It will be understood that a method based on this principle can be used with several sample tubes other than three, and any number of processing steps required for the extraction of specific biomolecules.

[0044] According to a fifth aspect of the present invention, a handheld device is provided that can hold a plurality of sample tubes and simultaneously manually stir or invert them, the device comprising a handle and a plurality of sample tube holding clips, each for holding its own sample tube.

[0045] The device may further include multiple restraint arms, each extending above one of the retaining clips to prevent the sample tube from falling out of the retaining clip when the device is inverted. Each restraint arm may be offset to one side of each retaining clip.

[0046] A sixth aspect of the present invention provides a method for simultaneously manually stirring or inverting a plurality of sample tubes, comprising the steps of inserting the sample tubes into an apparatus according to the fifth aspect, and operating a handle.

[0047] Optionally, at least one of the sample tubes may be attached to a lid assembly according to the first embodiment. Alternatively, optionally, at least one of the sample tubes may be a sample tube according to the third embodiment. Herein, embodiments of the present invention will be described with reference to the drawings, merely as examples. [Brief explanation of the drawing]

[0048] [Figure 1](a) A perspective view of a lid assembly for a sample tube, comprising a magnet holder that engages with a closure. (b) A perspective view of a magnet holder having a user-graspable portion to which a magnet is attached. (c) An exploded view of the magnet holder. (d) A perspective view of a closure including first and second finger tabs, a bead collection platform, and a magnet housing cavity in the form of a socket. [Figure 2] This is a perspective view of the underside of the closing section of Figure 1, showing the bead collection surface on the underside of the bead collection platform and an optional wicking member (in this case, the central wicking spike). [Figure 3] This is a perspective view of the lower surface of a modified version of the closing section of Figure 2, which does not have an optional wicking member. [Figure 4] This is a diagram of the lid assembly shown in Figure 1, with magnetic beads not present on the bead collection surface, and placed on the side. [Figure 5] Similar to Figure 4, this is a diagram of the lid assembly from Figure 1 placed on the side, with magnetic beads present on the bead collection surface. [Figure 6] This is a side view of the lid assembly in Figure 1, showing the magnetic beads held in place by the magnets in the magnet holder relative to the bead collection surface. [Figure 7] This figure shows the process of disengaging and separating the magnet holder in Figure 1 from its respective closing parts. [Figure 8] Figure 1 shows the lid assembly and sample tube, as well as the process of attaching the closure to the opening of the sample tube. [Figure 9] This figure further shows the lid assembly from Figure 1 attached to the sample tube in Figure 8. [Figure 10] This figure shows the process of disengaging and separating the magnet holders of the lid assembly in Figure 8 from their respective closures, with the closures attached to the sample tube. [Figure 11] Figure 10 shows (a) a cross-sectional side view of the disengagement process and (b) a cross-sectional side view of the separation process. [Figure 12]Figure 1 is a perspective view of the kit, which includes the lid assembly, three sample tubes, and a pipette (in this case, a volumetric pipette). [Figure 13] Figure 12 is a perspective view of a modified version of the kit, including additional sample collection tubes. [Figure 14] A further perspective view of the kit, as shown in Figure 12 or Figure 13, with the cover and backing panel. [Figure 15] Figure 1 is a perspective view of the three sample tubes connected to each other, along with the lid assembly. [Figure 16] This figure shows steps (a) to (l) of a method for collecting magnetic beads from a first liquid in a first sample tube, and then transferring the beads to a second liquid in a second sample tube. [Figure 17] A modified example of the lid assembly in Figure 1 is shown by (a) a perspective view, (b) a cutaway view of the closing section, and (c) a plan view of the closing section, in which case the magnet housing cavity is provided with a gripping protrusion for gripping the magnet holder. [Figure 18] The magnet holder and socket are equipped with threads that can engage with each other, and (a) an engaged cross-sectional view and (b) an unengaged perspective view of another modified example of the lid assembly shown in Figure 1. [Figure 19] This figure shows a modified version of the lid assembly in Figure 1, in which the first and second finger tabs of the closure are positioned to function as stands for supporting the lid assembly upside down with the sample tube attached. [Figure 20] This figure shows another modification of the lid assembly of Figure 1 attached to a sample tube, in which the user-grip portion of the magnet holder is configured to function as a stand for supporting the lid assembly and the attached sample tube in an upside-down orientation. [Figure 21] This figure shows a perspective view of a sample tube having a resealable cap that includes a removable cover and a compartment for containing reagent beads. [Figure 22]Figure 21 shows (a) an oblique cross-sectional view and (b) a cross-sectional view of the sample tube. [Figure 23] This figure shows a method using the sample tube shown in Figure 21, in which reagent beads are released into the liquid in the sample tube to perform colorimetric analysis and determine the presence or absence of a target species in the liquid. [Figure 24] Figure 1 is a perspective view of a handheld device that allows for the holding of multiple sample tubes and simultaneous manual stirring or inversion of them, using one such sample tube in a predetermined position with the lid assembly attached. [Modes for carrying out the invention]

[0049] In the drawings, similar elements are indicated by the same reference number throughout. This embodiment represents the best method known to the applicant for carrying out the present invention. However, it is not the only method that can achieve this.

[0050] overview This disclosure describes a rapid, low-cost, powerless extraction process for target biomolecules from liquid (or solid) samples. The target biomolecules may be polynucleotides, such as nucleic acids (e.g., RNA or DNA). For example, the target biomolecules may be, but are not limited to, characteristic RNA of certain viruses, such as SARS-CoV-2. This process does not require expensive laboratory equipment (such as centrifuges, vortex mixers, or micropipettes), power sources, or extensive prior training, and can be performed at virtually any location (i.e., away from the laboratory), such as a point of care. The entire process, from the initial sample (e.g., swab, saliva, tissue, or blood) to the extracted biomolecules (e.g., proteins, RNA, or DNA), can be performed by an untrained user in less than 5 minutes. This process is based on magnetic separation using magnetic beads (the term "magnetic beads" should be interpreted broadly, as outlined above). The principle of this extraction process is similar to that of other magnetic bead extraction kits and is not limited to the specific size or composition of the magnetic beads. In fact, for any given application, a person skilled in the art will understand that beads of appropriate size and composition should be used.

[0051] Referring first to Figure 8, this disclosure provides a lid assembly 100 for a sample tube 30. The sample tube 30 may be an existing sample tube, such as those manufactured by Eppendorf AG and commonly known as Eppendorf tubes (RTMs), the illustrated tubes having hinged caps and based on them. However, it should be noted that the principle of this disclosure is by no means limited to use with Eppendorf tubes (RTMs) and may be applied to sample tubes of different geometric shapes and dimensions, including tubes without hinged caps. Nevertheless, while the actual implementation form of this lid assembly 100 is designed to fit a specific diameter of a sample tube, there are no limitations (within a reasonable range) regarding the diameter of the sample tube to which the implementation form of the lid assembly 100 can be molded to fit. Typically, such a sample tube is several centimeters long, about 1 centimeter in diameter, and has a capacity of about 0.5 to 2 milliliters. When in use, the sample tube 30 contains a liquid in which magnetic beads are suspended. The lid assembly 100 can be used to collect magnetic beads from a liquid, and then release the beads into different tubes, typically containing different liquids.

[0052] As described in detail below, the lid assembly 100 comprises two main parts: a closure section 20 and a magnet holder section 10. The magnet holder section 10 is reversibly removable from the closure section 20 and incorporates a magnet, which is a neodymium magnet in our currently preferred embodiment, although other magnetic materials may be used instead. The closure section 20 has a bead collection surface 26. In use, to extract magnetic beads from the liquid in the sample tube 30 and capture them by the bead collection surface 26, the magnet holder section 10 is introduced into the magnet housing cavity in the closure section 20, thereby positioning the magnet behind the bead collection surface 26. When the magnet is in this position (and in practice, typically following a gentle inversion of the tube), the magnetic beads in the sample tube 30 are attracted by the magnet and held against the bead collection surface 26 under the influence of the magnet's magnetic field. Subsequently, the magnetic beads can be released from the bead collection surface 26 by removing the magnet holder section 10 from the closure section 20, thereby removing the magnetic field.

[0053] The lid assembly 100, when viewed from above, can typically have a footprint of approximately 2-3 cm x 1-2 cm, and its overall height (when the magnet holder 10 is attached to the closure 20) may be approximately 2-4 cm, although these measurements are merely approximations and examples. In any given case, the dimensions of the lid assembly 100 depend on the dimensions of the sample tube 30 into which it is designed to fit. The dimensions of the lid assembly 100 may also be designed to fit different hand sizes of users. Thus, the lid assembly 100 can be manufactured in a range of sizes to fit various sample tubes and be convenient and comfortable for various users.

[0054] The lid assembly 100 will first be described in detail, including the mechanism and method by which the magnet holder 10 is inserted into and engaged with the closing portion 20. Next, a method for attaching the lid assembly 100 to the sample tube 30 and using it will be described. Subsequently, several sample processing kits including the lid assembly 100 and the sample tube 30 will be presented, followed by a method for using the apparatus to extract target biomolecules from solid or liquid samples, for example, using magnetic separation. Finally, several variations and accessories of the apparatus will be described.

[0055] Lid assembly First, with reference to Figure 1, an example of the lid assembly 100 according to this disclosure will be described in detail here. Figure 1(a) shows the lid assembly 100 in a state where the magnet holding portion 10 is engaged with the closing portion 20.

[0056] -Magnet holding part 10 Figure 1(b) shows the magnet holder 10 alone, for example, removed from (or not yet inserted into) the closure 20, and Figure 1(c) is an exploded view of the same component. The magnet holder 10 comprises a magnet 18, which is advantageously a neodymium magnet, but other magnetic materials may be used instead. In the illustrated example, the magnet 18 is cylindrical, but other shapes are also possible.

[0057] The magnet holder 10 further comprises a body 12 which can be made of a plastic material (for example, by injection molding or 3D printing). The magnet 18 is attached to the body 12, for example, by adhesive. A recess can be provided on the underside of the body 12 to receive the magnet 18 and to precisely position the magnet for mounting. In other modifications, the recess and the magnet 18 can be configured to engage with each other in a press-fit manner, thereby eliminating the need for adhesive to hold the magnet in place. Alternatively, the magnet 18 may have a body 12 overmolded around it, so that the magnet is fused to the entire inside of the body 12.

[0058] The main body 12 primarily includes a user-gripable portion 13 that can be grasped by the user, typically between the thumb and index finger, in order to operate the magnetic holding portion 10 during use.

[0059] In the illustrated example of the magnet holder 10, the lower region of the main body 12 between the user-graspable portion 13 and the magnet 18 is in the form of a cylindrical shaft 14 having first and second radial projections 16a and 16b. As will be further described below, the cylindrical shaft 14 and the radial projections 16a and 16b enable the magnet holder 10 to rotatably engage with the closing portion 20.

[0060] -Closing part 20 Figures 1(d) and 2 show the closure 20 alone. The closure 20 may be made of a plastic material (e.g., by injection molding or 3D printing) and comprises a top 21 (flat or substantially flat), first and second finger tabs 24a, 24b that the user can grip and operate the closure during use, and a central bead collection platform 25 extending downward from the top 21. Optionally, the finger tabs 24a, 24b may have recessed or textured outer surfaces to improve user grip. The terms “top” (and similarly “upwards”) refer to the orientation of the closure 20 as shown in Figures 1 and 8, i.e., in situations such as when the closure 20 is attached to the sample tube 30, while “bottom” (and similarly “downwards”) are in the opposite direction to “top” and “upwards”.

[0061] The bead collection platform 25 has a bead collection surface 26 on one side and a magnet housing cavity 22 on the other side, both of which are aligned with the center of the closure 20. The bead collection platform 25 is positioned so that when the closure 20 is attached to the sample tube 30, it is located within (or potentially above, in an alternative embodiment) the opening of the sample tube 30, and as a result, the bead collection surface 26 is in contact with the liquid inside the sample tube 30 during use. The magnet housing cavity 22 is substantially in the form of a cylindrical (axial) socket and extends behind the bead collection surface 26 (as shown in the cross-section in Figure 11), and its primary function is to receive the magnet 18 of the magnet holder 10, if necessary.

[0062] Therefore, the magnet holder 10, and in particular the magnet 18, can be removably inserted into the magnet housing cavity 22 toward the bead collection surface 26. The cylindrical shape (i.e., circular cross-section) of both the magnet 18 and the shaft 14 of the magnet holder 10 allows the magnet holder 10 to be inserted downward and rotate within the cavity 22.

[0063] In the illustrated example, the magnet housing cavity 22 further comprises a pair of opposing longitudinal channels 22' molded to accommodate the radial projections 16a, 16b of the magnet holder 10, and a pair of circumferential channels 23 on which the radial projections 16a, 16b can rotate to engage widely in a non-spring-loaded bayonet mounting manner once the magnet 18 is fully inserted into the cavity 22.

[0064] Therefore, the magnet holder 10 is initially inserted linearly (non-rotatingly) into the magnet housing cavity 22 with its radial projections 16a and 16b aligned with the longitudinal channel 22'. Next, once the magnet 18 is fully inserted into the cavity 22, the user can engage the magnet holder 10 with the closing part 20 by rotating the magnet holder 10 relative to the closing part 20 so that the radial projections 16a and 16b move along the circumferential channel 23. In the illustrated example, the magnet holder 10 rotates clockwise relative to the closing part 20 when viewed from above to perform the engagement process.

[0065] As illustrated, each circumferential channel 23 may extend 90° around the cavity 22, so that the radial projections 16a, 16b reach the stop when the magnet holder 10 rotates 90° relative to the closure 20. The circumferential channels 23 may incorporate small recesses or stopper (or click) mechanisms to provide tactile feedback to the user when the radial projections 16a, 16b reach or approach the ends of each circumferential channel 23, and / or to lightly and reversibly lock the projections 16a, 16b at (or near) the ends of the circumferential channels 23. For example, in one embodiment, the mechanism may provide the user with a “click” effect that occurs when the magnet holder 10 rotates 45° relative to the closure 20. Such a “click” effect may be brought about by small protrusions (one on each radial projection 16a / 16b and one on each channel 23) passing each other and temporarily interfering as the magnet holder 10 rotates.

[0066] The operation of the magnet holder 10 and the closing part 20 is performed by the user grasping the user-graspable portion 13 of the magnet holder 10 with one hand and grasping the finger tabs 24a and 24b of the closing part 20 with the other hand, and moving the magnet holder 10 and the closing part 20 relative to each other.

[0067] Figure 2 shows the lower surface of the closure portion 20 of Figure 1. The bead collection surface 26 on the lower surface of the bead collection platform 25 can be seen to have a raised outer rim 29 (whose diameter is slightly larger than the rest of the bead collection platform 25), a concave or recessed area 28 for collecting magnetic beads during use, and an optional wicking member 27 in the center (in this case in the form of a wicking spike).

[0068] The wicking spike 27 helps prevent fluid carryover and retention of liquid on the bead collection surface 26, particularly when the lid assembly 100 is used to transfer magnetic beads from one sample tube to another (in which case it is generally undesirable for the beads to transfer any of the collected liquids). This effect is achieved by the wicking spike 27 breaking the surface tension of any such liquid, pushing the liquid down onto the spike 27 and prompting the removal of the closure 20 and any beads retained thereon. Centrifugation is not required to achieve this effect.

[0069] Figure 3 shows the underside of a modified 20' of the closure in Figure 2. Modified 20' is identical to that in Figure 2, except that it lacks an optional wicking member. Thus, the closure 20' has a larger central concave or recessed area 28, which can potentially collect a larger quantity of magnetic beads. Otherwise, the closure 20' has the same features and functions as the closure 20, and the two can actually be used interchangeably. Therefore, subsequent references to the closure 20 in this specification should be understood to include the possibility of using the closure 20' instead.

[0070] In alternative modifications of the modifications shown in Figures 2 and 3, region 28 may have a convex (or dome-shaped) profile instead of a concave profile. Such a convex (or dome-shaped) profile can facilitate the drying of the magnetic beads when collected on the surface by exposing them more to the ambient air circulating around them.

[0071] Referring, for example, to Figures 8 and 11, the closure 20 includes means for removably attaching the closure 20 to the opening of the sample tube 30 in order to close the sample tube 30. In the illustrated embodiment, the means for removably attaching the closure 20 to the opening of the sample tube 30 is provided by a bead collection platform 25, which is molded to fit snugly to the opening of the sample tube 30 in a press-fit manner, broadly like a stopper, thereby enabling quick and easy attachment (and subsequent removal) of the lid assembly 100 to the sample tube 30.

[0072] The sealing of the closure portion 20 by the opening of the sample tube 30 is also reinforced by the rim 29 of the bead collection surface 26, which has a diameter slightly larger than the rest of the bead collection platform 25, and forms a compression fit with the inner wall of the sample tube 30 in an essentially press-fit manner. Thus, the rim 29 advantageously provides two functions: holding magnetic beads within the concave region 28 and forming a compression fit with the inner wall of the sample tube 30.

[0073] In other variations of the closure 20, alternative means may be provided for removably attaching the closure 20 to the opening of the sample tube 30. For example, the closure 20 may incorporate a snap-fit ​​mechanism or a threaded configuration to engage with a complementary mechanism of the sample tube.

[0074] The bead collection platform 25, which extends downward from the center of the upper part 21, will be understood to have air all around it when the closure 20 is not attached to the sample tube 30. This allows the bead collection surface 26 to hold the magnetic beads 42 largely exposed to air when detached from the sample tube (but still protected by the first and second finger tabs 24a, 24b, which extend parallel to the bead collection platform 25 but are separate from the bead collection platform). This allows any liquid on the beads to evaporate quickly before the beads are resuspended in the next liquid, thereby avoiding contamination of the next liquid by the preceding liquid. Such evaporation typically takes only about 30 seconds and does not require additional drying equipment.

[0075] Furthermore, once the bead collection surface 26 is inserted into the subsequent sample tube 30, the unobstructed nature of the bead collection surface 26 allows the magnetic beads 42 to be easily removed from the lid assembly 10 and resuspended in the liquid contained within the subsequent tube 30 by gently shaking or inverting the tube in the absence of the magnet 18.

[0076] For example, referring to Figures 4, 5, 8, and 10, the upper part 21 of the closure portion 20 preferably has an elongated shape when viewed from above or below, allowing it to be comfortably fitted onto a sample tube 30 having a hinged cap 34 (see, for example, Figure 8) without soiling the hinge 36 or the cap 34.

[0077] More specifically, as shown in Figures 4 and 5, the upper part 21 of the closure 20 may have an elongated irregular hexagonal shape when viewed from above or below, having two opposing sides formed by the first and second finger tabs 24a, 24b and four further sides 22a, 22b, 22c, 22d. The sides 22a and 22b, as well as the sides 22c and 22d, intersect at obtuse angles. This allows the closure 20, and indeed the entire lid assembly 100, to rest on its surface on the surface 40 without rolling off, as shown in Figures 4 and 5. The elongated irregular hexagon shown is only one possible shape of the closure; other shapes, such as rectangles or semicircles, are also achievable.

[0078] Figures 5 and 6 are diagrams of the lid assembly 100 of Figures 1, 2 and 4, specifically showing magnetic beads 42 on a bead-collecting surface 26 within a concave or recessed area 28. The side view of Figure 6 shows that the first and second finger tabs 24a, 24b can also be used as stands to support the lid assembly 100 upright on a surface 40. Thus, the first and second finger tabs 24a, 24b extend below the bead-collecting surface 26 (and beyond the wicking member 27), and as a result, the magnetic beads 42 remain away from the surface 40 and are not contaminated by the surface.

[0079] Therefore, the first and second finger tabs 24a and 24b protect the magnetic beads 42 on the bead collection surface 26 from accidental contact with the surface 40 and (at least to some extent) the user's fingers.

[0080] When the magnet 18 is located within the magnet housing cavity 22 (i.e., inserted inside), the magnet 18 can hold magnetic beads against the bead collection surface 26. That is, the bead collection surface 26 can be used to collect magnetic beads 42 suspended in the liquid in the sample tube 30. This is because the magnetic beads 42 are attracted towards the magnet 18 under the influence of the magnet's magnetic field, and as a result, the beads 42 are held against the bead collection surface 26.

[0081] Conversely, if the magnet 18 is not present in the magnet storage cavity 22 (i.e., not inserted or removed), Lid assembly 100 Since there is no magnetic field to pull the beads toward the bead collection surface 26, the magnetic beads cannot be magnetically held toward the bead collection surface 26. Therefore, by removing the magnet 18 from the magnet housing cavity 22, the magnetic beads 42 held toward the bead collection surface 26 can be released from the bead collection surface 26.

[0082] To maximize the tensile effect of the magnet 18 on the magnetic beads 42 (when inserted into the cavity 22) and to hold them against the bead collection surface 26, a strong magnet such as a neodymium magnet (i.e., one that generates a strong magnetic field) is preferably used.

[0083] - Removal of the magnet holding part 10 from the closing part 20 The magnet holder 10 can be disengaged and separated from the closure 20 by reversing the insertion and engagement process described above. Such a disengagement and separation process is shown in Figure 7. First, (a) the magnet holder 10 is rotated 90° counterclockwise relative to the closure 20 as indicated by arrow R, disengaging the first and second radial projections 16a and 16b from their respective circumferential channels 23, and thus aligning the first and second radial projections 16a and 16b with their respective longitudinal channels 22' (Figure 1(d)). Next, (b) the magnet holder 10 is lifted upward from the magnet housing cavity 22 in the direction of arrow U. This results in (c) the magnet holder 10 being separated from the closure 20. As described above, the operation of the magnet holding part 10 and the closing part 20 is performed by the user grasping the user-graspable part 13 of the magnet holding part 10 with one hand and grasping the finger tabs 24a and 24b of the closing part 20 with the other hand, and moving the magnet holding part 10 and the closing part 20 relative to each other.

[0084] - Step of attaching the lid assembly 100 to the sample tube 30. As shown in Figure 8, the lid assembly 100 can be attached to a sample tube 30, for example, an Eppendorf tube (RTM). Such a tube 30 has a body including a straight region 31 and a tapered end region 32, with an opening 33 at the top surrounded by a rim 35. As shown, the sample tube 30 may have an openable / closable cap 34 connected to the rim 35 of the tube by a flexible hinge 36. When in the closed position, the cap 34 seals the opening 33 of the tube. The cap 34 has a finger tab 37 that prompts the user to open the cap and an internal plug portion 38 that is located inside the rim 35 of the tube when the cap is closed.

[0085] During use, in order to attach the lid assembly 100 to the tube 30, the cap 34 (if present) of the tube 30 is first opened, and then the lid assembly 100 is positioned in the direction of arrow D and engages with the bead collection platform 25 in the opening 33 of the tube 30 in a press-fit manner, and the rim 29 of the bead collection surface 26 forms a compression fit with the inner wall of the tube 30. As shown in Figure 9, the operation of the lid assembly 100 is performed by the user. One hand This is done by grasping the finger tabs 24a and 24b of the closure section 20 with one hand and holding the tube 30 with the other, and bringing them together. Note that this press-fit installation method is quick and easy.

[0086] Figure 10 shows the process of disengaging and separating the magnet holder 10 of the lid assembly 100 from its respective closure 20, with the closure 20 remaining attached to the sample tube 30. First, (a) the magnet holder 10 is rotated 90° counterclockwise relative to the closure 20, as indicated by arrow R, as described above in relation to Figure 7. Next, (b) the magnet holder 10 is retracted upward from the magnet housing cavity 22 in the direction of arrow U. As a result, (c) the magnet holder 10 is separated from the closure 20. As described above, such operations on the magnet holder 10 and the closure 20 are performed by the user grasping the user-graspable portion 13 of the magnet holder 10 with one hand and the finger tabs 24a, 24b of the closure 20 with the other hand (with the closure 20 gripping the tube 30), and moving the magnet holder 10 and the closure 20 relative to each other.

[0087] Alternatively, the user can simply grasp the sample tube 30 with one hand (with the closure 20 attached) and rotate and retract the magnet holder 10 with the other hand. The reverse procedure can be used when introducing and engaging the magnet holder 10 with the closure 20 on the sample tube 30 while in the field.

[0088] Figure 11 is a cross-sectional side view of the disengagement process (a) and the separation process (b) in Figure 10. The cross-sectional shapes of the magnet 18, the bead collection platform 25, the bead collection surface 26, and the magnet housing cavity 22 are also noteworthy.

[0089] It can be seen that the magnet 18 and the magnet housing cavity 22 are sized such that when the magnet holding portion 10 engages with the closing portion 20, the magnet 18 contacts (or comes very close to) the bottom of the cavity 22. Furthermore, in order to bring the magnet 18 as close as possible to the bead collection surface 26, thereby maximizing the influence of the magnet's magnetic field on the magnetic beads 42 in the tube 30, it is preferable to make the thickness of the material between the bead collection surface 26 and the magnet housing cavity 22 as thin as possible while simultaneously maintaining a reliable level of strength and robustness.

[0090] The cross-sectional profile of the bead collection surface 26 can also be seen, which has a raised outer rim 29, a concave or recessed area 28 for collecting magnetic beads, and an optional wicking member 27 in the center.

[0091] In alternative modifications of the closure 20, the bead collection surface 26 may have a flat or convex shape. Regardless of the overall profile of the bead collection surface 26, yet another possibility is to incorporate therein an array of indentations or recesses where magnetic beads 42 are attracted to and held on the surface 26. This is intended to achieve a uniform distribution of beads across the bead collection surface 26 so as to prevent the beads from agglomerating, resulting in improved drying ability and easier subsequent release from the surface 26 when the magnet 18 is removed.

[0092] kit Referring to Figures 12 to 14, the disclosure also provides a kit comprising the lid assembly 100 as described above, one or more sample tubes 30, and optionally a pipette 54 and / or a swab, and / or a further sample collection tube 55 (Figure 13).

[0093] For example, Figure 12 shows a kit 50 including a lid assembly 100, three sample tubes 30, and a pipette 54 (in this case, a pipette of precise volume). The kit 50 includes an inexpensive but useful packaging tray 52 made of molded (e.g., thermoformed) plastic, which also functions as a stand for the sample tubes 30 and the lid assembly 100. More specifically, the tray 52 incorporates several dedicated recesses or cavities 51 (integrally formed during the molding of the tray) where the sample tubes 30 are placed, and a dedicated recess 51' where the lid assembly 100 is placed, thus holding the sample tubes 30 and the lid assembly 100 in an upright orientation and eliminating the need for additional laboratory equipment such as tube racks. In fact, the kit can be used on any surface, including the user's knees while seated, and therefore does not require a bench or tabletop. The tray 52 also has an outwardly extending rim 53 that increases the overall rigidity of the tray 52.

[0094] In this figure, the tubes 30 are subsequently labeled A, B, and C, and these labels are referenced when describing how such tubes are used with the lid assembly 100 to perform extraction of target biomolecules from a sample, for example, using magnetic separation.

[0095] Figure 13 is a perspective view of a modified version 50' of the kit in Figure 12. As shown, the kit 50' may further include (or be designed to accept) additional sample collection tubes 55 which can also function as sample inactivation tubes. Additional dedicated recesses or cavities 51” may be formed in the tray 52 to hold the tubes 55 in an upright orientation. The tubes 55 may be obtained externally rather than being provided as part of the kit 50'. By inserting the tubes 55 into the dedicated recesses or cavities 51” the user can spatially correlate a given sample with the rest of the kit 50', thus holding all the tubes of a given sample together and reducing the possibility of any mix-up with tubes from another nearby kit. Kit 50' is also shown with a removable backing sheet 58 (which may be made of cardboard or plastic) in place.

[0096] As shown in Figure 14, such a kit may also include a removable cover 56, also made of molded (e.g., thermoformed) plastic, extending over the tube 30 and lid assembly 100 and other contents. The cover 56 is attached to a backing sheet 58 during manufacturing and has a rim 57 that holds the rim 53 of the tray 52 against the backing sheet 58 for transport purposes, sterilizing and holding the components within in place. The cover 56 also incorporates molded features 59 that fit around the magnetic holder 10 of the lid assembly 100 when the kit is closed, holding the lid assembly 100 in place during transport. When removed for use, the cover 56 can, once used, function as a waste container for the sample tube 30 and other contents of the kit, or as a temporary intermediate preparation area. As shown, the cover 56 incorporates a peel-off corner 57' which is part of the rim 57. The peeling corner 57' is raised relative to the rest of the rim 57, allowing for easy opening of the cover 56 and removal of the cover 56 from the backing sheet 58, thus opening the kit and freeing the tray 52 for use. As will be understood by those skilled in the art, other means are possible for removably attaching the cover 56 to the tray 52, for example by a snap-fit ​​mechanism between the cover 56 and the tray 52, which is formed integrally as part of the thermoforming process of the cover 56 and the tray 52.

[0097] As shown in Figure 15, another kit 60 provided by this disclosure includes a plurality of sample tubes 30 (in this case, three) connected to one another by connecting components 62. Connecting the tubes 30 in this manner facilitates the stepwise processing of magnetic beads from tube to tube. Kit 60 also includes a lid assembly 100 that can be used with any tube 30 (conveniently by moving the lid assembly sequentially, i.e., from A to B, then to C, from tube to tube). Optionally, the last of the sample tubes 30 (in this case, tube C) may be connected to its adjacent tube (tube B) by a fragile connection 64 so that the last tube (C) can be easily removed from the other tubes and taken out separately for subsequent processing. Of course, it will also be understood that such fragile connections 64 may be provided between any of the connected tubes 30 as needed.

[0098] In all of the above kits (50, 50', and 60), the sample tube 30 may be supplied already containing various liquids (examples of which are described below). Furthermore, the liquid in the first sample tube 30 may be pre-filled with magnetic beads 42.

[0099] However, if there are problems with the long-term stability of the magnetic beads 42 in the liquid in the first sample tube 30, the magnetic beads 42 may be pre-filled into the first sample tube 30 and the liquid may be placed in a separate container. For example, the liquid may be provided in a separate tube (e.g., a mold-filled tube, though not necessarily) or in a disposable tear-open sachet, capsule, or blister pack from which the liquid can be transferred (e.g., squeezed) into the first sample tube 30 as needed. Such a blister pack may be pre-attached to the opening of the first sample tube 30, so that the user only needs to press the blister pack to burst its underside (e.g., consisting of film or foil) and release the liquid into the first sample tube 30 in order to mix it with the magnetic beads 42. The blister pack can then be removed from the opening of the first sample tube 30.

[0100] Alternatively, the liquid in question may be supplied into the first sample tube 30, and the magnetic beads 42 may be provided in a separate container, sachet, capsule, blister pack, or mold-filled tube, from which they may be transferred to the first sample tube 30 as necessary, in the same manner as the liquid described above. Method for collecting magnetic beads from liquid in a sample tube

[0101] Referring first to Figure 16 and its steps (a) through (f), the present disclosure provides a method of using the lid assembly 100 to collect magnetic beads 42 from a liquid 44 in a sample tube 30 in which the beads 42 are suspended in the liquid 44. For clarity, the reference numbers in Figure 16 are not repeated for each step, but it should be understood that the same items are used for each step unless otherwise specified. Features of the lid assembly are referenced using the reference numbers assigned to the preceding drawings. This method will be described in relation to collecting magnetic beads 42 from the liquid 44 in sample tube A, starting from step (a) in Figure 16.

[0102] As shown in step (a), the method first includes the step of the user opening the sample tube 30 (in fact, the tube is closed with a cap. The method is equally applicable to use with a tube that does not have a cap and is therefore already open, in which case step (a) is omitted).

[0103] Next, as shown in step (b), the method includes the step of attaching the closing portion 20 of the lid assembly 100 to the opening 33 of the sample tube 300, thereby resulting in the configuration shown in step (c). As described above, in the currently preferred embodiment, the attachment method is by engaging the bead collection platform 25 in the opening 33 of the tube 30 in a press-fit manner, and the rim 29 of the bead collection surface 26 forms a compression fit with the inner wall of the tube 30. Note that at this stage, the magnet holder 10, more specifically the magnet 18, is inserted into the magnet housing cavity 22 of the closing portion 20 (and is optionally locked if a locking mechanism as described above is provided).

[0104] Next, as shown in step (d), the method includes gently stirring the liquid 44 by, for example, gently inverting the sample tube 30 or gently shaking the liquid 44, as a result of the magnetic beads 42 The magnetic beads 42 come into contact with the bead collection surface 26 and are held against the bead collection surface 26 by the magnet 18. The diagram in step (d) shows the inclination of the magnetic beads 42 as they converge toward the bead collection surface 26. In practice, the process of collecting the magnetic beads 42 onto the bead collection surface 26 takes several seconds.

[0105] Next, as shown in step (e), the magnetic beads 42 are collected on the bead collection surface 26 of the lid assembly. As a result, the liquid in the tube is now clear (i.e., there are no beads).

[0106] Referring here to step (f) and beyond, the method may further include the step of the user removing the lid assembly 100 from the sample tube A while the magnet 18 is still inserted into the magnet housing cavity 22 and the magnetic beads 42 are held against the bead collection surface 26 by the magnet 18.

[0107] Sample tube A may be considered the first sample tube, and the liquid 44 contained within it may be considered the first liquid. There may be at least a second sample tube 30 (here referred to as sample tube B) containing a second liquid 46 from which the magnetic beads 42 are to be released and resuspended. Thus, the method may further include the step of opening sample tube B (if sample tube B is actually closed, as shown in step (g)), and then, as shown in step (h), attaching the closure portion 20 of the lid assembly 100 to the opening 33 of the second sample tube (tube B) containing the second liquid 46. At this stage, the magnetic beads 42 remain held against the bead collection surface 26 of the lid assembly 100.

[0108] Next, in order to release the magnetic beads 42 from the bead collection surface 26 as shown in steps (i) and (j), the method further includes the step of the user removing the magnet 18 from the magnet housing cavity 22 so that the magnetic beads 42 are no longer held to the bead collection surface 26 by the magnet 18. As outlined above with reference to Figures 10 and 11, removal of the magnet 18 may require the user to first rotate the magnet holder 10 (for example, in the counterclockwise direction R) as shown in step (i), and then retract the magnet holder 10 upward (in the U direction) to separate it from the closure 20. At this stage, since the magnet 18 is no longer present, the magnetic beads 42 are no longer magnetically held to the bead collection surface 26.

[0109] As shown in step (k), in order to resuspend the magnetic beads 42 in the second liquid 46, the user can gently agitate the liquid 46 by, for example, gently inverting the sample tube B or gently shaking the liquid 46, so that the magnetic beads 42 come into contact with the liquid 46, are swept away from the bead collection surface 26, and resuspended in the liquid. At this stage, it is possible for at least some of the beads 42 to fall into the liquid 46 without requiring such agitation of the liquid, but the resuspendion of the beads 42 in the liquid 46 is performed more quickly and completely when such agitation is performed. This results in the configuration shown in step (l), where the magnetic beads 42 are suspended in the second liquid 46 in tube B.

[0110] It will be understood that by continuing the above method, the magnetic beads 42 can be extracted from tube B and transferred to a third sample tube containing the third liquid (for example, tube C as illustrated in the above kit). Therefore, following step (l) above, this method is The steps include reinserting the magnet 18 into the magnet housing cavity 22, The steps include stirring the second liquid 46 so that the magnetic beads 42 come into contact with the bead collection surface 26 and are held against the bead collection surface 26 by the magnet 18, With the magnet inserted into the magnet housing cavity 22 18 and the magnetic beads 42 held against the bead collection surface 26 by the magnet, the lid assembly 100 is removed from the second sample tube (tube B), The steps include attaching the closing portion 20 of the lid assembly 100 to the opening of the third sample tube (tube C) containing the third liquid, The method further comprises the step of removing the magnet 18 from the magnet housing cavity 22 so that the magnetic beads 42 are no longer held in place by the magnet 18 against the bead collection surface 26 and are suspended in the third liquid (after the third liquid has been agitated against the bead collection surface 26 as necessary).

[0111] It will be understood that the above method can be carried out quickly and easily, taking into account the press-fit method for attaching the lid assembly 100 to various sample tubes 30, the corresponding ease with which the lid assembly 100 can be removed from the sample tubes, and further considering the simple method by which the magnet holder 10 can be removed from or attached to the closure 20.

[0112] The ease of use of this device is further enhanced by the tray 52, which functions as a stand for various components during use, thus facilitating the completely manual use of the components without the need for other tube racks or stands, and eliminating the need for the user to place anything on the external surface. This is particularly important when the tubes are open, during the transfer of magnetic beads, as placing open tubes on the external surface increases the risk of contamination of the contents. The device, including the tray / stand 52, also advantageously facilitates one-handed use of the device, which can be beneficial at times.

[0113] A method for extracting target biomolecules from a sample using magnetic separation. To illustrate the advantages of the lid assembly 100 of the present invention and the above method in practical situations, a method for performing the extraction of target biomolecules from a liquid (or solid) sample using magnetic separation will be described using the lid assembly 100 and magnetic beads 42 (in this case, particularly magnetic nanoparticles). This method will again be described with reference to Figure 16.

[0114] To summarize this method, target biomolecules such as DNA / RNA / proteins are first released from the sample via a lysis buffer and then bound to magnetic nanoparticles with a binding buffer. These beads are then washed with a washing solution to remove contaminants / chemicals and undesirable biological molecules from the previous step. After washing, the purified analyte is eluted (released) from the beads via an elution buffer (e.g., molecular-grade water or Tris-EDTA(TE) buffer). The eluted analyte (e.g., RNA) can then be used for downstream molecular applications such as polymerase chain reaction (PCR) processing or isothermal amplification, according to user requirements. It should be understood that "Tris" is an abbreviation for tris(hydroxymethyl)aminomethane and EDTA is an abbreviation for ethylenediaminetetraacetic acid.

[0115] Therefore, to carry out this method, first, second, and third sample tubes (e.g., tubes A, B, and C in the above kit) containing the first, second, and third liquids, respectively, are used. In a general sense, the first liquid is a dissolution / binding buffer for dissolving the target biomolecules, thereby releasing them into the solution and binding the biomolecules to the magnetic beads. The second liquid is a washing solution. The third liquid is an eluent for eluting the biomolecules. Referring to Figure 16 for more details, this method includes the following steps.

[0116] Preliminary step 1: Biological samples (e.g., nasal secretions suspected to contain viral particles such as SARS-CoV-2 particles) are collected using a nasopharyngeal swab and placed in a sample collection tube 55 (e.g., a so-called eNAT(RTM) tube) containing inactivation buffer.

[0117] Preliminary step 2: Using pipette 54 (preferably a disposable pipette of the exact volume), a fixed amount of inactivation buffer containing the virus particles eluted from the swab is transferred from sample collection tube 55 to the first sample tube 30, i.e., tube A in Figure 16, and the mixture is gently shaken. Tube A is pre-filled with lysis / binding buffer (e.g., guanidinium thiocyanate-based, optionally containing a solvent such as isopropanol or ethanol) and magnetic beads 42, which also contain the virus particles eluted from the swab. The magnetic beads 42 have a silica coating that binds to nucleic acids from the virus particles.

[0118] Now, referring to Figure 16, Step (a): Open the cap of tube A. Step (b): Lift the lid assembly 100 (with the magnet holder 10 engaged with the closing part 20) up to tube A. Step (c): Attach the lid assembly 100 to tube A. Step (d): Gently invert the tube A to which the lid assembly 100 is attached to collect the magnetic beads 42 onto the bead collection surface 26 via magnetic attraction. Step (e): The magnetic beads 42 are collected on the bead collection surface 26 of the lid assembly 100. As a result, the liquid in the tube is now clear (no beads). Step (f): Remove the lid assembly 100 holding the magnetic beads 42 from tube A. Step (g): Open the second sample tube 30, i.e., tube B in Figure 16. Tube B contains the washing solution (e.g., a solution of 80% ethanol). Step (h): Attach the lid assembly 100 holding the magnetic beads 42 to tube B. Steps (i) and (j): The magnet holder 10 is disengaged from and removed from the closing portion 20, and as a result, the magnetic beads 42 are no longer magnetically held to the bead collection surface 26. Step (k): The magnetic beads 42 are separated from the bead collection surface 26 and resuspended in the washing solution by gently inverting or shaking tube B, thereby washing the beads and removing contaminants / chemicals and undesirable biological molecules from the previous step. This results in the configuration shown in step (l).

[0119] Following step (l), this method further includes the following steps.

[0120] Step (m): The magnet holder 10 is reinserted into the magnet housing cavity 22 of the closure 20 (which is still attached to tube B). Step (n): Gently invert the tube B to which the lid assembly 100 is attached to collect the magnetic beads 42 onto the bead collection surface 26 via magnetic attraction. Step (o): Remove the lid assembly 100 holding the magnetic beads 42 from tube B. Step (p): The magnetic beads 42 on the removed lid assembly 100 are exposed to air for 30 seconds to evaporate the cleaning solution (in this case, ethanol solution). If a kit 50 as shown in Figure 12 is used, the lid assembly 100 can be advantageously placed in a dedicated recess 51' at this stage, allowing the magnetic beads 42 to dry while keeping the lid assembly 100 and the beads 42 away from potential sources of contamination. Step (q): The lid assembly 100 holding the magnetic beads 42 is attached to the opening of the third sample tube (tube C) containing the eluent. Step (r): The magnet holder 10 is disengaged from the closing part 20 and removed, and as a result, the magnetic beads 42 are no longer magnetically held to the bead collection surface 26. Step(s): The magnetic beads 42 are separated from the bead collection surface 26 and resuspended in the eluate by gently inverting tube C, causing the elution of the analyte in question (e.g., characteristic RNA of the viral particles mentioned above) for subsequent processing.

[0121] To optionally remove the magnetic beads 42 from the eluate, the method may further include the following additional steps.

[0122] Step (t): The magnet holder 10 is reinserted into the magnet housing cavity 22 of the closure 20 (which is still attached to tube C), and the tube C is gently inverted to extract the magnetic beads 42 from the eluate, thereby recovering the magnetic beads 42 on the bead collection surface 26 via magnetic adsorption. As a result, only the eluted analyte (e.g., the characteristic RNA of the above-mentioned virus particles) remains in the eluate for subsequent processing. Step (u): At this point, the lid assembly 100 can be removed from tube C and discarded together with the used magnetic beads 42. The magnet holder 10 may be stored and reused as needed.

[0123] The entire process from sample (e.g., nasopharyngeal swab, saliva, or blood) to RNA extraction can be performed in less than 5 minutes by a virtually untrained user at the point of care.

[0124] - Experimental verification of the above method The above techniques were experimentally implemented, and comparative tests were conducted using the "gold standard" column-based extraction method of the Qiagen:QIAamp viral RNA mini-kit. Cultured SARS-CoV-2 (10 7 A total of six samples containing PFU / mL were analyzed using both methods, and the extracted RNA was quantified by RT-qPCR targeting the E gene. The recovery results averaged 3 × 10⁶ for both the Qiagen kit and this technique. 10 and 1.4 × 10 10 The method demonstrated comparable performance in total RNA copies. These promising results indicate that the simple, rapid, and easy extraction method of the present invention can compete very favorably with conventional laboratory-based extraction techniques that require expensive equipment and electricity and result in delays of more than 30 minutes.

[0125] - Advantages of the above method and apparatus Traditionally, sample preparation has played a crucial role in analytical science. This method overcomes the limitations of existing expensive, time-consuming, and complex molecular extraction kits by providing a novel approach that enables rapid (less than 5 minutes) extraction processes of different molecules from different sources of clinical samples (e.g., different types of swabs and biological samples). The currently disclosed method and apparatus provide a cost-effective, robust, and safe, disposable kit that requires minimal steps / time and reagents, does not require centrifugation or vortexing, does not require electricity, does not use expensive equipment, does not require detailed prior training, and can be easily implemented in low-resource or remote settings. The above advantages and other advantages are obtained by the following:

[0126] • Use of the above controllable and magnetizable lid assembly 100 for a disposable (e.g., Eppendorf (RTM)) sample tube to collect magnetic beads 42 and transfer target particles attached to the magnetic beads through one or more subsequent sample preparation steps (e.g., dissolution / binding, washing, elution). • A cap assembly that can fit any type of tube (e.g., threaded top, snap top, etc.) or size (e.g., 0.5ml, 1ml, 1.5ml, etc.). • A magnet 18 that can be removed from the closure 20 to allow for easy resuspension of the beads at each step as needed. The ability to move magnetic beads 42 through multiple pre-filled tubes, rather than adding / removing chemicals or solutions to / from a single tube containing the beads. • Design of a cover assembly to protect the magnetic beads 42 from accidental surface contact or user contact (e.g., as shown in Figures 5 and 6). To prevent liquid retention due to surface tension, wicking members (e.g., wicking spikes) are optionally placed on the bead collection surface 26.

[0127] Compared to existing technologies, the use of this lid assembly achieves or enables the following: • Eliminate the need for electrical equipment (such as centrifuges, vortex mixers, commercial power-connected heaters, and safety cabinets). • Eliminates the need for expensive micropipettes for transferring liquids. • The use of silica-based membranes is not required to purify the product. • Reduce the minimum extraction time required by commercially available kits (at least 30 minutes) to less than 5 minutes. • Eliminates the need for a laboratory-based environment and commercial power supply, and therefore can be used as a point-of-care extraction method in remote locations. The kit currently described (where the package / tray functions as a stand) does not require any other tube racks or stands, and the user does not need to place anything on the external surface, thus reducing the risk of contamination of the inspection equipment and liquids. In fact, the kit can be used on any surface, including the user's knees when seated, so a bench or tabletop is not required. • The kit is suitable for storage at room temperature (freezing is not required). • Extraction does not require highly skilled personnel. • Extremely simple, typically less than 1 GBP per sample.

[0128] Modification examples, alternative examples, and accessories Detailed embodiments and several possible alternatives are described above. As those skilled in the art will understand, several modifications and further alternatives can be made to the embodiments described above, but still benefit from the invention as embodied therein.

[0129] In the above embodiment of the lid assembly 100, the magnet holder 10 is completely separable from the closing portion 20 and can be inserted into the magnet housing cavity 22 of the closing portion 20, and the magnet 18 is positioned close to the back of the bead collection surface 26 to attract the magnetic beads 42 toward and onto the bead collection surface 26.

[0130] However, alternative configurations of the lid assembly may still be envisioned based on the principle of bringing the magnet closer to the rear side of the bead collection surface to attract the magnetic beads to the front side (facing the liquid) of the bead collection surface as needed, and moving the magnet away from the rear side of the bead collection surface when it is not necessary to attract the beads to the surface (i.e., when the magnetic beads are released).

[0131] For example, the magnet does not need to be part of a completely separable magnet holder. Instead, the magnet or magnet holder may remain coupled to the closure while being controllable movement toward or away from the rear of the bead collection surface. In one such example, the magnet holder may be attached to the closure. In another example, the detachability of the magnet holder from the closure may be restricted by a restraining mechanism, while still allowing the magnet holder to move toward or away from the rear of the bead collection surface. Such movement may (but does not) be linear. For example, in another modification, the magnet may be movable toward or away from the rear of the bead collection surface by a rocker switch mechanism. Another configuration for controllably advancing or retracting the magnet relative to the rear of the bead collection surface can use a push-button mechanism, widely similar to that of a retractable ballpoint pen.

[0132] In the above-described embodiment of the lid assembly 100, the engagement process between the magnet holder 10 and the closing portion 20 includes linearly inserting the magnet holder 10 into the cavity 22 of the closing portion 20, and then rotating the magnet holder 10 relative to the closing portion 20 (for example, up to 90°) to engage the first and second radial projections 16a, 16b along their respective circumferential channels 23.

[0133] However, as shown in Figure 17, a modification of the lid assembly 100a may omit the rotational engagement principle and related features and use only linear insertion to engage the magnet holder 10a with the closure 20a (as indicated by the double arrows in Figure 17(a)). Thus, the shaft 14 of the magnet holder 10a is smooth and lacks the radial projections 16a, 16b in Figure 1. Similarly, as shown in Figures 17(b) and 17(c), the magnet housing cavity 22 of the closure 20a lacks the circumferential channel 23 in Figure 1. However, to provide a certain engagement, the closure 20a may incorporate a gripping means (in this case, a longitudinal projection / bump 47) for gripping the magnet holder 10a within the magnet housing cavity 22. In all other respects of materials, the features of the lid assembly 100a are the same as those of the lid assembly 100 described above (for example, as shown in Figure 1).

[0134] In the case of a device where rotational engagement between the magnet holder 10 and the closing part 20 is not required, the shaft 14 of the magnet holder 10 does not need to be cylindrical, and may instead have a non-rotatable cross-sectional shape (for example, a square shape).

[0135] It should also be noted that even with the aforementioned lid assembly 100, which provides linear insertion of the magnet holder 10 and the closing part 20, and subsequent rotational engagement, the rotational step can be omitted after the magnet 18 is inserted into the cavity 22, if the user so desires, for example, to further expedite the process. However, in such circumstances, the user must take care to prevent the magnet holder from accidentally separating from the closing part 20 at an inappropriate moment, for example, by applying gentle pressure on the magnet holder 10 to hold it in place.

[0136] Figure 18 shows (a) an engaged cross-sectional view and (b) an unengaged perspective view of another modification 100b of the lid assembly of Figure 1, wherein the magnet holder 10b and the closing portion 20b include threads 48 (optionally multi-start threads) that can engage with each other. With respect to all other materials, the features of the lid assembly 100b are the same as those of the lid assembly 100 described above (for example, shown in Figure 1).

[0137] With respect to the above-described embodiment of the lid assembly 100, it has been explained that the first and second finger tabs 24a, 24b extend downward from the bead collection surface 26 and can therefore be used as a stand for supporting the lid assembly 100 in an upright orientation on the surface 40 (as shown in Figure 6). However, under certain circumstances, it may be advantageous to be able to support the lid assembly upside down with the sample tube 30 attached, for example, to allow gravity to assist in the collection of magnetic beads 42 on the bead collection surface 26. For this purpose, Figure 19 shows another modification 100c of the lid assembly of Figure 1, in which the first and second finger tabs 24a', 24b' of the closure portion 20c extend both downward and upward from the bead collection surface 26 to a degree sufficient to function as a stand for supporting the lid assembly 100c upside down with the sample tube 30 attached (and similarly, and alternatively, in an upright orientation without the sample tube attached). In terms of all other materials, the features of lid assembly 100c are the same as those of lid assembly 100 described above (for example, shown in Figure 1).

[0138] In yet another variation (not shown), the first and second finger tabs of the closure may extend only above the bead collection surface (i.e., the opposite side of Figure 6) to a degree sufficient to allow the lid assembly to function as a stand that can only support the lid assembly upside down (with the sample tube optionally attached).

[0139] Figure 20 shows another modification 100d of the lid assembly of Figure 1, in which the user-graspable portion 13' of the magnet holder 10' has a wide cross-sectional profile (in this case, cruciate) that can function as a stand for supporting the magnet holder 10' upside down. This is an alternative to the user-graspable portion 13, which has a relatively thin and flat shape as shown in Figure 1 and is not suitable for stably supporting the magnet holder 10 upside down without assistance. Preferably, as shown in Figure 20, the cross-sectional profile of the illustrated modification of the user-graspable portion 13' provides a sufficiently stable stand so that it can also support the attached closure 20 and the attached sample tube 30 upside down if necessary.

[0140] - Modified sample tube and instructions for use As shown in Figures 21 and 22, the disclosure also provides a modified sample tube 30' which is a variation of the sample tube 30 described above.

[0141] Similar to the conventional sample tube described above, the modified sample tube 30' has a body including a linear region 31 and a tapered end region 32, with an opening 33 at the top surrounded by a rim 35. (It will be understood that other geometric shapes of the modified sample tube 30' are also possible, i.e., it does not necessarily have to have a linear region 31 or a tapered end region 32 as shown.) The sample tube 30' further comprises an openable cap 34 connected to the rim 35 of the tube by a flexible hinge 36. The cap 34 has a tab 37 that prompts the user to open the cap.

[0142] However, in contrast to conventional sample tubes, the cap 34 of the modified sample tube 30' further includes a compartment 38' for containing a certain amount of reagent (which may be in the form of beads 70 or tablets, as illustrated). The compartment 38' has a removable cover 39 made of, for example, foil or plastic film, which seals the contents of the compartment 38'. The cover 39 may be provided with an integral pull-out tab 39' which first folds into the rest of the cover 39 to allow for quick and easy removal of the cover 39 if necessary. It will be understood that the compartment 38' is located inside the cap 34 and within the rim 35 of the tube 30' when the cap is closed.

[0143] The reagent (e.g., beads 70) is inserted into compartment 38' in the manufacturing facility and covered with cover 39. During manufacturing, compartment 38' may preferably be sealed with cover 39 in a low-oxygen environment to maximize the lifespan of the reagent.

[0144] As illustrated, the reagent may, advantageously, be in the form of beads 70 or tablets, thereby facilitating the loading of the reagent into compartment 38', enabling long-term storage at room temperature, and allowing the entire reagent to be passed out of compartment 38' as a single unit into the body of the tube. However, alternatively, the reagent may be in the form of a dry powder, or a liquid or gel.

[0145] When the cover 39 is removed from compartment 38' and the cap 34 is closed over the opening 33 of the tube 30' during use, the reagent may be loose in compartment 38' so that it simply falls into the body of the tube and into any liquid therein. Such falling of the reagent can be facilitated if the reagent is in the form of beads 70 or tablets, as outlined above.

[0146] Alternatively, if the reagent is in the form of beads 70 or tablets (or a solid), it can be securely fitted into compartment 38' by press-fitting it into a molded recess within compartment 38', thereby preventing the reagent beads 70 from accidentally falling out of the compartment (e.g. onto the floor) when the cover 39 is removed and the cap 34 is moved to its closed position. Once the cover 39 is removed from compartment 38' and the cap 34 is closed onto the body of tube 30, the user may need to use the liquid in the tube to flush / dissolve the reagent beads 70 out of compartment 38' by inverting tube 30' using the amount of reagent thus press-fitted.

[0147] The reagent (e.g., beads 70) may be any chemical substance. However, following the above method of extracting a target biomolecule (such as characteristic RNA of a particular virus) from a sample using magnetic separation, the reagent may also be a lyophilized colorimetric detection reagent, which may be introduced into the eluate containing (or potentially containing) the eluted target biomolecule and the presence or absence of the target biomolecule determined by colorimetric analysis.

[0148] Therefore, in the above method, tube C (containing the eluent) may be a modified sample tube 30', and the reagent beads 70 are preferably lyophilized colorimetric detection reagents in bead or tablet form. Such tube C, pre-filled with the eluent and pre-prepared with lyophilized colorimetric detection reagent beads 70 in a sealed compartment 38' inside the cap 34 of the tube, may form part of one of the above-described kits (for example, shown in Figures 12 to 15).

[0149] Figure 23 illustrates this colorimetric analysis process. In step (a), the reagent beads 70 are released from the cap compartment 38' of the sample tube 30', and as a result, in step (b), the reagent beads 70 enter the eluate 72 in the body of the sample tube. At this stage, the reagent beads 70 rapidly dissolve and mix with the eluate 72. All the chemical species necessary to perform nucleic acid amplification (e.g., PCR or LAMP) of a target biomolecule (e.g., viral RNA) are now available, and this study will demonstrate that they can be provided in a kit form suitable for remote use by substantially untrained users.

[0150] To carry out the colorimetric amplification process, it may be necessary to heat the contents of the 30' sample tube to, for example, about 63°C and hold it at such a temperature for a period of time, such as about 20 minutes. This amplifies the target nucleic acid, if present, thereby changing the color of the liquid. This is shown as step (d) in Figure 23. On the other hand, if the target nucleic acid is not present, amplification does not occur, as shown in step (c) of Figure 23, and as a result, the color of the liquid does not change.

[0151] When performed in a remote location away from a power source, the above heating can be provided by a chemical heat pack (for example, one that is "snapped" to activate, causing an exothermic reaction and releasing heat) or by a small battery-powered or solar-powered heater block into which a 30' sample tube can be inserted. Therefore, it will be understood that all aspects of this disclosure are suitable for use in remote locations.

[0152] -reagent More generally, the reagents described above (e.g., beads 70) may include various chemical species or other species (e.g., enzymes, primers, etc.) required for various nucleic acid amplification methods, as well as mixtures thereof.

[0153] For example, nucleic acid amplification methods may include polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR), quantitative PCR (qPCR), reverse transcription qPCR (RT-qPCR), nested PCR, multiplex PCR, asymmetric PCR, touchdown PCR, random primer PCR, heminested PCR, polymerase cycling assembly (PCA), colony PCR, ligase chain reaction (LCR), digital PCR, methylation-specific PCR (MSP), co-amplification PCR at low denaturation temperature (COLD-PCR), allele-specific PCR, sequence-specific PCR (ISS-PCR), whole-genome amplification (WGA), reverse PCR, or thermally asymmetric interlaced PCR (TAIL-PCR). In some embodiments, the nucleic acid amplification reaction may be isothermal nucleic acid amplification. Isothermal amplification is a form of nucleic acid amplification that does not depend on the thermal denaturation of the target nucleic acid during the amplification reaction and therefore does not require multiple rapid temperature changes. Thus, isothermal nucleic acid amplification can be performed inside or outside the laboratory environment. Many isothermal nucleic acid amplification methods have been developed, including but not limited to strand displacement amplification (SDA), transcription-mediated amplification (TMA), nucleic acid sequence-based amplification (NASBA), recombinase polymerase amplification (RPA), rolling circle amplification (RCA), lamination amplification (RAM), helicase-dependent isothermal DNA amplification (HDA), circular helicase-dependent amplification (cHDA), loop-mediated isothermal amplification (LAMP), single-primer isothermal amplification (SPIA), signal-mediated amplification of RNA technology (SMART), self-amplifying sequence replication (3SR), genome index amplification (GEAR), and isothermal multiplexing amplification (IMDA). Further examples of such amplification chemistry are described, for example, in "Isothermal Nucleic Acid Amplification Techniques for Point-of-Care Diagnostics: An Important Review" (Pascal Craw and Wamadeva Balachandrana Lab Chip, 2012, 12, 2469-2486, DOI: 10.1039 / C2LC40100b).

[0154] In certain currently preferred embodiments, the reagent (e.g., beads 70) may contain components for constructing either of the above amplification chemistrys suitable for pH-based detection or colorimetric detection (e.g., pH-LAMP). This may be achieved, for example, by reducing the buffering capacity (perhaps by the absence of Tris-HCl). The reagent (e.g., beads 70) may encompass a wide range of chemistry for visual (or other) detection of the target species, providing amplification indication.

[0155] For example, in certain embodiments, the amplification indicator may be an organic or inorganic compound added to the nucleic acid amplification reaction mixture so that its content in the solution (such as the presence or absence of a particular nucleic acid) can be visually determined.

[0156] In certain embodiments, the amplification indicator substance may be a metal ion indicator (also called a complex titration indicator or metallochromic indicator), which is an uncomplexed indicator (e.g., Ca 2+ Mg 2+ Zn 2+ These are substances that change color after forming metal ion complexes (including, but not limited to, metal ions) that have a different color from the color of the metal ions themselves.

[0157] Other amplification indicators well known to those skilled in the art include, but are not limited to, hydroxynaphthol blue, eriocrom black t, karmagite, curcumin, fast sulfone black, hematoxylin, murexide, xylenone orange, BAPTA, BAPTA AM, BTC, BTC AM, calcein, calcein AM, calcein Blue, calcium green 1, calcium green 2, calcium green 5N, coelenterazine, coelenterazine cp, coelenterazine f, coelenterazine h, coelenterazine hcp, coelenterazine n, corona green, corona green AM, corona red, DAF FM, Fluo 3, Fluo 3 AM, PBFI AM, Phen Green SK, Quin 2, Quin 2 AM, and RhodZin 3.

[0158] In other embodiments, the amplification indicator substance may be a pH indicator. As those skilled in the art will understand, the pH indicator is a hydronium ion (H3O + ) or hydrogen ions (H + A chemical detector is a chemical detector. Typically, an indicator changes the color of a solution according to its pH. Indicators can also indicate changes in other physical properties. For example, olfactory indicators indicate changes in their odors.

[0159] Other possible amplification indicators include, but are not limited to, gentian violet, malachite green, thymol blue, methyl yellow, bromophenol blue, Congo red, methyl orange, screened methyl orange (first transition), screened methyl orange (second transition), bromocresol green, methyl red, methyl purple, azolitmine red, bromocresol purple, bromothymol blue, phenol red, neutral red, naphtholphthalein, cresol red, cresolphthalein, phenolphthalein, thymorphaline, alizarin yellow R yellow, and indigo carmine.

[0160] In other embodiments, the amplification indicator substance may be a redox indicator (also called an oxidation-reduction indicator), which is an indicator dye that undergoes a distinct color change at a specific electrode potential. There are two common types of redox indicators: pH-independent redox indicators and pH-dependent redox indicators.

[0161] Examples of pH-independent redox indicators include, but are not limited to, 2,2'-bipyridine, nitrophenanthroline, N-phenylanthranilic acid, 1,10-phenanthroline iron(II) sulfate complex, N-ethoxychrysoidin, 2,2'-bipyridine, 5,6-dimethylphenanthroline, o-dianisidine, sodium diphenylaminesulfonate, diphenylbenzidine, diphenylamine, and viologen.

[0162] Examples of pH-dependent redox indicators include, but are not limited to, sodium 2,6-dibromophenol-indophenol, sodium o-cresolindophenol, thionine, methylene blue, indigotetrasulfonic acid, indigotrisulfonic acid, indigocarmine, indigomonosulfonic acid, phenosafranin, safranin, and neutral red.

[0163] In the above discussion, the reagent is described as being in the form of beads 70 attached to the cap compartment 38' of the modified sample tube 30', but it will be understood that a certain amount of the reagent (e.g., in the form of beads 70) can be provided in other ways for introduction into the eluent at the appropriate time. For example, the reagent beads 70 (or an amount of the reagent in another form) may be provided in a separate tube (e.g., a mold-and-fill tube, though not necessarily), a container, or a tear-off packet / sachet, which may be opened at the appropriate time to allow the reagent to be transferred into the sample tube containing the eluent. Such a tube, container, or tear-off packet / sachet containing the reagent may be provided as part of one of the kits described herein.

[0164] - A handheld device for manually stirring or inverting multiple sample tubes. Finally, in practice, to save time, it may be desirable to manually stir or invert multiple sample tubes 30 / 30' simultaneously (with or without the main lid assembly 100 attached). To achieve this, Figure 24 shows a handheld device 80 for holding multiple sample tubes 30 / 30' and for manually stirring or inverting them simultaneously without requiring power. One of these sample tubes 30 is shown held in place with the main lid assembly 100 attached.

[0165] More specifically, the apparatus 80 comprises a handle portion 82 and a plurality of sample tube holding clips 84 for holding each sample tube 30 / 30'. The plurality of holding clips 84 are attached to a transverse member 86 that is perpendicular to the handle portion 82 and extends on both sides thereof.

[0166] The device 80 further comprises a plurality of restraint arms 88, each restraint arm 88 extending above each of the retaining clips 84. The restraint arms 88 are positioned to restrain the sample tube when the device 80 is inverted. 30 / 30’ This helps prevent it from falling off the retaining clip 84.

[0167] From Figure 24, it can be seen that each restraint arm 88 is offset to one side of its respective retaining clip 84. This is the sample tube to which the main lid assembly 100 is attached. 30 / 30’ This is to accommodate the above. By being offset in this way (referring again to Figure 1, for example), each restraining arm 88 does not contaminate the magnet holding portion 10 of the lid assembly 100 (specifically, the user-graspable portion 13), but instead acts on one side of the magnet holding portion 10 against the upper portion 21 of the closing portion 20.

[0168] The apparatus 80, including the retaining clip 84 and the restraining arm 88, can be formed as a single structure from a plastic material, for example by injection molding or 3D printing. The illustrated apparatus 80 has nine sample tubes. 30 / 30’ Although shown as having the capability to support, this is merely an example, and other numbers of retaining clips 84 and restraining arms 88 are certainly possible.

[0169] Accordingly, the Disclosure also provides a manual method for simultaneously stirring or inverting a plurality of sample tubes 30 / 30', comprising inserting the sample tubes 30 / 30' into the apparatus 80 and operating the handle portion 82 to simultaneously stir or invert the tubes. Optionally, at least one of the sample tubes may be attached to the lid assembly 100 described above. Also, optionally, at least one of the sample tubes may be the modified sample tubes 30' described above. No power is required to perform this manual method for simultaneously stirring or inverting the sample tubes 30 / 30', and it will be understood that it is therefore suitable for use in remote locations or low-resource settings.

Claims

1. A lid assembly for a sample tube for collecting magnetic beads from the sample tube and subsequently releasing the beads, The aforementioned lid assembly It is a closed section, The closing part is detachably attached to the opening of the sample tube during use, and is a means for closing the sample tube. A bead collection platform disposed such that the closing portion is located within the opening of the sample tube when the closing portion is attached to the sample tube, the bead collection platform having a bead collection surface on one side for contact with the liquid inside the sample tube during use, and a magnet housing cavity on the other side behind the bead collection surface, A closed section including, A magnet holder comprising a magnet, wherein when the magnet is located within the magnet housing cavity, the magnet can hold magnetic beads relative to the bead collection surface, and when the magnet is not located within the magnet housing cavity, the lid assembly cannot magnetically hold magnetic beads relative to the bead collection surface, the magnet is removablely insertable into the magnet housing cavity toward the bead collection surface. The means for removably attaching the closing portion to the opening of the sample tube comprises a press-fit portion adapted to engage with the opening of the sample tube during use, The press-fit fitting portion is the bead collection platform. Lid assembly for sample tubes.

2. The magnet holding portion is separable from the closing portion, Alternatively, the lid assembly according to claim 1, wherein the magnet holding portion is coupled to the closing portion, allowing the magnet to move within the magnet housing cavity toward or away from the bead collection surface.

3. The magnet holding portion further comprises a user-graspable portion to which the magnet is attached. The lid assembly according to claim 1 or claim 2.

4. The lid assembly according to any one of claims 1 to 3, wherein the magnet housing cavity is in the form of a socket molded to receive at least the magnet of the magnet holding portion.

5. The lid assembly according to claim 4, wherein the magnet holding portion is rotatable within the socket.

6. The lid assembly according to claim 4 or 5, wherein when the magnet is inserted into the magnet housing cavity, the magnet holding portion and the closing portion are engageable with each other.

7. The lid assembly according to claim 6, wherein the magnet holding portion comprises one or more radial projections, and the socket comprises one or more complementary channels into which the one or more radial projections can engage.

8. The lid assembly according to claim 6, wherein the magnet holder and the socket are equipped with threads that can engage with each other.

9. The lid assembly according to any one of claims 4 to 8, wherein the socket comprises a gripping means for gripping the magnet holding portion.

10. The lid assembly according to any one of claims 1 to 9, wherein the closing portion is provided with first and second finger tabs on both sides of the closing portion so that it can be gripped by the user's thumb and fingers when in use.

11. The lid assembly according to claim 10, wherein the first and second finger tabs extend below the bead collection surface and can function as stands for supporting the lid assembly in an upright orientation when separated from the sample tube.

12. The lid assembly according to claim 10 or 11, wherein the first and second finger tabs extend above the bead collection surface and can function as stands for supporting the lid assembly upside down.

13. The bead collection surface incorporates a concave or recessed area, Alternatively, the bead collection surface may be convex, Alternatively, the lid assembly according to any one of claims 1 to 12, wherein the bead collection surface incorporates an array of recesses or indentations.

14. The lid assembly according to any one of claims 1 to 13, wherein the bead collection surface incorporates a fluid wicking member.

15. A kit comprising a lid assembly according to any one of claims 1 to 14, and at least a first sample tube.

16. A method for collecting magnetic beads from a liquid in a sample tube, wherein the method is The steps include attaching the closing portion of the lid assembly according to any one of claims 1 to 14, or the closing portion of the lid assembly of the kit according to claim 15, to the opening of the sample tube, The step of stirring the liquid with the magnet inserted into the magnet housing cavity such that the magnetic beads come into contact with the bead collection surface and are held against the bead collection surface by the magnet, A method for collecting magnetic beads from a liquid in a sample tube, comprising the following:

17. The sample tube is a first sample tube that contains a first liquid, and the method is With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the first sample tube. The steps include attaching the closing portion of the lid assembly to the opening of the second sample tube containing the second liquid, The steps include removing the magnet from the magnet housing cavity so that the magnetic beads are no longer held in place by the magnet against the bead collection surface and are suspended in the second liquid, The method according to claim 16, comprising:

18. The steps include: reinserting the magnet into the magnet housing cavity; The step of stirring the second liquid so that the magnetic beads come into contact with the bead collection surface and are held in place by the magnets relative to the bead collection surface, With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the second sample tube. The steps include attaching the closing portion of the lid assembly to the opening of the third sample tube containing the third liquid, The steps include removing the magnet from the magnet housing cavity so that the magnetic beads are no longer held in place by the magnet against the bead collection surface and are suspended in the third liquid, The method according to claim 17, further comprising:

19. The steps include: reinserting the magnet into the magnet housing cavity; The step of stirring the third liquid so that the magnetic beads come into contact with the bead collection surface and are held in place by the magnets relative to the bead collection surface, With the magnet inserted into the magnet housing cavity and the magnetic beads held in place by the magnet against the bead collection surface, the lid assembly is removed from the third sample tube. The method according to claim 18, further comprising:

20. The first liquid is a dissolution / binding buffer for binding biomolecules to the magnetic beads, The second liquid is a cleaning solution, and The method according to claim 18 or claim 19, wherein the third liquid is an eluent for eluting the biomolecules.

21. The method according to claim 20, further comprising the steps of introducing a detection reagent into the eluate and applying heating as necessary to determine the presence or absence of the biomolecule.

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