Patent Application
20240367162
Microfluidics and conventional pipettor-based robotics are well known techniques for processing and creating chemical and biological products. Some implementations of these methods comprise a consumable element, e.g., a microfluidic chip or tubing, vials, reactors, test tubes, pipette tips, etc. as well known in the art.
An objective according to some embodiments is to minimize the consumable materials needed to conduct a chemical or biological process. An objective according to other embodiments is to take full advantage of capabilities offered by a motion stage.
In accordance with an embodiment, an apparatus includes a motorized traverse, a flow controller, a tip-mount traverse, and a tip, and also includes a motion of a tip past an influencer.
In an embodiment, the influencer is a non-uniform magnetic field.
In another embodiment, the influencer is an absorbent material.
In yet another embodiment, the influencer is a thermal interface material in communication with a thermal source. The thermal source may be a Peltier module.
In accordance with another embodiment, an apparatus includes a motorized traverse, flow controller, a tip mount traverse, and a tip including a motion past an actuatee.
In an embodiment, the actuatee is the tip-mount traverse.
In another embodiment, the actuatee is a plug retainer in a station that applies and removes a tip plug.
In accordance with another embodiment, an apparatus includes a floss, a floss-advancing reel, a floss wetter, and a tip cleaning region.
In an embodiment, the apparatus also includes a traverse motion profile that wipes the surface of the tip across a floss.
In accordance with yet another embodiment, an apparatus includes a motor, a rotor having an eccentric bearing hole and taper that leads to the bearing hole, and a vibration damping element that acts on a surface region of a tip inserted into the eccentric hole.
As used herein, a ‘process’ generically refers to at least one step comprising a physical, chemical, or biological manipulation. Physical manipulations may comprise but are not limited to aliquoting, diluting, distilling, fractionating, pipetting, washing, mixing, diffusing, convecting, vortexing, osmosing, heating, cooling, ultrasonic agitating or cavitating, mechanically interacting, magnetically interacting, electrostatically interacting, optically interacting, electrophoresis, electroosmosing, dielectrophoresis, electroporating, patch-clamping, centrifuging, etc. Chemical manipulations may comprise but are not limited to reacting, electrochemically interacting, charge transferring, changing of an energy state, titrating, buffering, desalting, dialyzing, labeling, separating, etc. Separations may employ chromatography, electrochromatography, isotachophoresis, etc. Biological interactions may comprise but are not limited to incubating, in vitro synthesizing (IVT), polymerase chain reacting (PCR), vaccinia tagging, tagging, lysing, transfecting, etc.
A process herein may be a chain of steps completed serially, in parallel, or in an arbitrary combination of parallel and serial steps.
As used herein ‘enchamber’ may mean physically to contain. Enchambering elements may comprise a barrier to diffusion, evaporation, convection, reaction, and electric, magnetic, thermal, optical fields, etc.
As used herein ‘tip’ may refer to an enchambering vessel having at least one port, such as a disposable pipette tip. On a two-port tip, the ‘actuator port’ may refer to an opening of a tip designed to seal to a pipettor, through which hydraulic or pneumatic fluids pass bidirectionally, and the ‘reagent port’ may refer to an opening of the tip through which reagent and reactant fluids pass bidirectionally.
It is well known in the field to use a tip to transfer liquids to and from vials and other chambers via mechanical motion during a process. It is also known in the art to use microfluidic channels to enchamber processes and route liquids via fluid motion. Some embodiments of the present invention comprise a hybrid mobile microfluidic circuit which may employ mechanical motion as well as fluid motion and process enchamberment.
As used herein a ‘tip station’ may comprise the apparatus at a site where a tip may be located for an operation such as storage, thermal cycling, elution, infusion, separation, vortexing, missing, centrifugation, refrigeration, freezing, etc.
In some embodiments of the present invention, the mobile microfluidic device or tip comprises a single-port, a two-port, or a multiple port chamber. In some embodiments, the microfluidic device comprises a plurality of chambers. In some embodiments, at least one such chamber is connected fluidically to a second such chamber. Some embodiments further comprise a filter element, e.g., a barrier filter as known in the art. Some embodiments further comprise a surface modification. Some embodiments comprise at least one surface modification on one or more of: an interior surface, an exterior surface, a chamber surface, a partial chamber surface.
In some embodiments of the present invention, the mobile microfluidic device may comprise a disposable tip as known in the art. In some embodiments, the tip may further comprise a barrier filter as known in the art.
Advantages of a hybrid mobile microfluidic device may be:
Disadvantages may be:
Cross contamination may be alleviated by a ‘tip cleaning’ method and apparatus according to some embodiments of the present invention.
The uncertainty in gas/liquid interface position may be alleviated by a ‘plug-centering’ or ‘normalization’ method and apparatus according to some embodiments of the present invention.
While the language and imagery employed in this disclosure depict a pipette tip as the mobile microfluidic element, this depiction is not intended to be limiting. Other embodiments of mobile microfluidic elements may comprise a vessel having more than two ports, a tube, a capillary, a microfluidic chip, a chamber, a multiple-port fluidic circuit.
Intentional tip distortions may be unknown in conventional pipetting.
Axial fluid motion within the tip may be combined with translational motion and distortional motion to achieve a desired function.
Some embodiments of infusion comprise a larger infusion of the second buffer fluid, shown in the view 4400 of
An embodiment of the present invention may comprise apparatus to detach a tip. An embodiment of the present invention may comprise apparatus to attach a tip. Some embodiments may comprise apparatus that may be used both to attach and to detach a tip.
It is common in the art to attach a tip by pressing a conical mount into a conical lead-in section of a tip, the tip seal being made substantially by a normal force between the mount and lead-in section via elastic preload, and the attachment achieved by friction produced by this preload. It is common to employ a motion robot for this purpose. It is common in the art to detach a tip by pressing axially along an extent of the top rim of the tip.
It is common in the art to attach a tip by rotating mating thread portions on a tip and a mount, e.g., a ‘luer’ lock as known in the art. Such an attachment may use the same action (a relative rotation) to mount or dismount.
Some embodiments of the present invention comprise one or more of a ‘tip cap,’ a ‘lock,’ a ‘pressure interface,’ a ‘pressure interface seal’, a ‘tip seal’, a ‘mounting interface,’ a ‘lock detente’, an ‘alignment pin.’
Some embodiments of a tip cap may comprise a rigid, or semi-rigid, rubber, elastic, plastic, metal, or composite mount having an opening port to pass fluid between a pressure interface and tip.
To effect a mounting restraint force, some embodiments of tip caps comprise one or more of: a frictional bearing surface, a normal-force bearing surface, a partial thread, a clip, a ratcheting mechanism, a pneumatic mechanism, a hydraulic mechanism.
To effect a seal between the tip cap and tip, some embodiments of tip caps comprise a conical cylindrical outer surface. Some such embodiments seal to the tip in part via an elastically generated normal force. Some tip-cap embodiments comprise at least one outer groove to accommodate an o-ring to effect or enhance a seal. Some embodiments comprise at least one outer, substantially circumferential rib. Some embodiments may comprise a pneumatically or hydraulically inflated/deflated seal.
Some embodiments of tip caps may comprise an element to prevent transport of material between the tip and surroundings when the pressure interface is detached. Some embodiments of tip caps comprise an elastic septum as known in the art. Some embodiments of tip caps, may further comprise a valve. Some embodiments of a tip cap valve may be in the open state when the cap is engaged with a pressure interface. Some embodiments of tip caps may further comprise a filter, such as a barrier filter.
Some embodiments of tip caps may comprise an element to attach to a pressure interface. Some such embodiments may comprise one or more of: a frictional bearing surface, a normal bearing surface, a partial thread, a locking mechanism, a hydraulic mechanism, a pneumatic mechanism.
Some embodiments of tip caps may comprise an element to attach to a pressure interface. Some such embodiments may comprise one or more of: a normal-force preload, an o-ring seal, an elastic septum, a swage, a circumferential ring, a circumferential cavity.
As used herein, a ‘state’ may be a position, orientation, or mechanical configuration. Some embodiments of tip caps and locks may comprise a mechanism that mechanically resists detachment in at least one state. Some such embodiments may further comprise at least one state, or configuration that does not mechanically resist detachment. Some embodiments of tip cap locks may comprise an element that overcomes a bearing friction force at a state or range of states between the first and second state.
Some embodiments of locks may further comprise one or more additional states. In some embodiments, an additional state may comprise a fluidic configuration such as one or more of the following: a pressure-interface vented state, a pressure-interface unvented state, a tip-vented state, a tip-unvented state. An additional state may comprise a mechanical configuration such as a rotation-resisting state, a rotation enabling state, a partial detachment state, a mechanically unconstrained state, a mechanically relaxed state, a mechanically rigid state.
Some embodiments of locks may comprise one or more of: a ramp, a slot, a keyhole slot, a partial thread, a slide, a ratchet, a clip, a clamp, a pneumatic mechanism, a hydraulic mechanism.
Some embodiments comprise at least one détente that relaxes toward a state. Some embodiments of détentes employ one or more of: an elastic interaction, a flexure, a magnetic interaction, an electrostatic interaction, a ratchet.
Some embodiments of pressure interfaces comprise an element that mates to a complementary seal element on a tip cap. Some embodiments further comprise one or more of an o-ring, a hydraulic or pneumatic actuated seal, a mechanical-actuated mount. Some embodiments comprise at least one sliding or rotating surface in mechanical communication with one or more of: a mount, a lock, a cap, a tip, a tip station.
Some embodiments of locks or pressure interfaces according to the present invention may further comprise one or more alignment features. Some embodiments employ such a feature for one or more of: to establish a known state from an initially uncertain state, to reduce an actuation force on a tip, to establish an alignment between a tip and tip station. Some such embodiments comprise a pin, a cone, a ball, a partial thread, a concavity, a convexity, or a mating geometry thereof. Some embodiments may comprise a mating geometry to an alignment feature on a tip station.
Conventional pipettors may comprise a positive displacement pump, such as a piston pump or syringe pump to control infusion and elution, herein called ‘flow control.’ Embodiments of the present invention comprise a flow controller comprising one or more of: a pump, a valve, a sensor. Some embodiments of a pump according to the present invention comprise a positive-displacement pump, a piston pump, a syringe pump, a gear pump, a diaphragm pump, an impeller pump, an ultrasonic pump, etc. Some embodiments of sensors comprise one or more of a pressure sensor, a flow sensor, a meniscus sensor, a bubble sensor, an absorption sensor, a reflection sensor, a scattering sensor. Some embodiments of valves employ pressure, mechanical, magnetic, solenoidal, motor actuation, or thermal actuation. Some valve embodiments comprise a check valve, an on-off valve, a metering valve, a needle valve, a rotary valve, a swept-volume valve. Some valves comprise a three-port valve having one common position and two ports as known in the art. Some valves comprise a four-port valve as known in the art. Some valves comprise a six-port valve as known in the art.
In some embodiments the role of a flow-controller valve is to allow a finite-volume piston pump to refill or empty so it can elute or infuse into a pipette tip a volume that exceeds the volume of the piston's cylinder. This may confer the advantage of high-accuracy microdosing into comparatively large tip volumes without a loss of accuracy or the need to dilute.
In some flow-controller embodiments one or more of a flow-controller valve or pump is used in concert with a feedback sensor. In some embodiments a feedback sensor is used to meter a displaced volume. In some embodiments, a feedback sensor is used to establish a known meniscus position. Some embodiments of flow-controllers rely solely on positive displacement to establish a known meniscus position.
Some embodiments of the present invention mount flow-controller hardware in the reference-frame of the pressure interface. Some embodiments mount the flow-controller hardware in the reference frame of a traverse stage and connect via a flexible conduit to the pressure interface. Some embodiments mount in a substantially stationary reference frame and connect to the pressure interface via a longer flexible conduit.
Tip cleaning may be important for preventing cross contamination of reagents during infusions. In some embodiments, a liquid infusion may be followed by a small infusion of a buffer fluid such as air, an inert gas, carbon dioxide, reactant gas, etc. to break contact of the liquid plug from any residual pendant or stuck drops on the tip exterior.
Some embodiments of the present invention wipe/abrade/press the contaminated end of the tip on or through an absorbent surface. In some embodiments the surface is pre-wetted with a solvent, e.g., water, an alcohol, an organic solvent, or a mixture, a detergent solution, or cleaning agent. In some embodiments, the cleaning procedure iterates. In some embodiments, the solvent type and saturation of absorbent surface is altered from one iteration to the next. In some embodiments, the final iteration or iterations may produce a substantially dry surface.
In some embodiments, uncontaminated absorbent surface is used for each cleaning iteration. In some embodiments, this is achieved by wiping on a different zone of an absorbent sheet. In some embodiments this is achieved by wiping on a ‘tape’ or ‘floss’ that is advanced during or in between iterations.
As used herein, a ‘sheet’ may be a flexible object, having a length and width that is much greater than a thickness. As used herein, a ‘tape’ may be a flexible object having a length that is much greater than a width, and a width that is greater than a thickness. As used herein, a ‘floss’ may be a flexible object having a length that is much greater than a width and a width and thickness that are comparable. Some embodiments of sheets may be random or aligned arrangements of fibers, papers, tissues, fabrics, gauzes, etc. Tapes may be strips of random or aligned fibers, strips of paper, strips of woven fibers, etc. Some embodiments of flosses may be yarns, threads, collections of random, aligned, or twisted fibers, braided or woven fibers or threads, etc. The composition of a sheet, tape, or floss may be materials having a desired physical or chemical characteristic, such as nap, wettability, hydrophobicity, hydrophilicity, abrasiveness, etc. Some tapes or flosses according to the present invention may comprise a mixture of component fibers, binders, surface modifiers, gels, surfactants, oils, greases, pastes, particles, powers, etc. In some embodiments, a mixture may be tailored to clean a particular type of reagent from a tip surface. In some embodiments a mixture may be tailored to clean a range of reagent types from a tip surface.
In some embodiments, the absorber contains features that inhibit wicking of contaminates or liquids from one region to another. In some embodiments, a wicking inhibitor is applied to at least one region of a sheet, tape, or floss. In some embodiments a wicking inhibitor is induced in a region by one or more of: a pressure, a force, a high temperature treatment, a chemical treatment, an optical treatment, a laser.
In some embodiments the absorber contains features that promote wicking of contaminates or liquids within a region of a sheet, tape, or floss. In some embodiments, such a feature may be applied via mechanical disruption of an inhibitive layer, thermal treatment, optical treatment, plasma treatment, electrical discharge, electret creation, chemical treatment, solvent treatment.
Some embodiments of tip cleaning stations comprise a collection of a clean tape or floss, herein called the ‘source roll.’ Some embodiments of tip cleaning stations further comprise a collection of used tape or floss, herein called the ‘waste roll.’ Some embodiments of these collections may be spindle-rolled, flaked, wound, bobbined, balled, or alternatively disposed.
Some embodiments of the present invention comprise an actuator that can pull a tape or floss. Some embodiments of actuators may comprise a capstan or pinching mechanism. Some embodiments may comprise a reel or roll mechanism. Some embodiments employ a motor or solenoid to actuate the mechanism. Some embodiments comprise at least one mechanical element that allows a motion traverse to actuate the mechanism.
Some embodiments of cleaning stations comprise a source roll, a waste roll having features to facilitate its actuation by a motion stage, a ‘wetting station’ wherein a cleaning solution or solvent is introduced to the floss or tape and the floss or tape is spatially constrained, a ‘take-up interface’ wherein the floss or tape is constrained is spatially constrained, and a cleaning region disposed between the wetting station and take-up interface. Some embodiments comprise a single floss or tape and some embodiments comprise a plurality of flosses or tapes that run substantially parallel or a plurality of flosses that cross each other within the cleaning region.
Some embodiments comprise a ‘liquid doser’ that supplies a dose of cleaning liquid or solvent to the wetting station. Some embodiments of liquid dosers comprise a pump mechanism that can be actuated by motion of a traverse, such as a spring-returned check-valve pump, piston pump, eye-dropper, droplet-on-demand generator or other mechanical pump as known in the art. Some alternative embodiments comprise an electrically actuated pump as known in the art. Some embodiments of dosers may comprise a gas or air gap between the pump exit and wetting station to prevent back contamination of the cleaning solution or mechanisms.
Some embodiments of cleaning stations employ a motion traverse to actuate a ‘cleaning motion’ of a tip relative to a floss or tape that may wipe and abrade the tip on the floss or tape surface.
Some embodiments may comprise a rotation of the tip about its axis combined with motion along the axis of the floss or tape. In some embodiments this motion is combined with motion along the axis of the tip.
Some embodiments of cleaning motions may comprise lowering a tip adjacent to a flow or tape, moving the tip substantially transversely to interfere with the floss or tape, sliding the tip substantially along the axis of the floss or tape in combination with sliding the tip up or down along the axis of the tip so that one side of the tip surface is wiped by the floss or tape. Some embodiments may optionally advance the floss or tape, then perform substantially a mirror image of this motion on the other side of the floss or tape to clean the other side of the tip. Some embodiments may comprise motion back and forth, in a zig-zag motion transverse to or along the axis of the floss or tape. Some embodiments may comprise a circular or elliptical helical motion of the tip relative to the floss or tape.
Some embodiments comprise a plurality of flosses that cross within the cleaning region. The cleaning motion in such an embodiment may comprise lowering the tip between the crossing threads followed by a motion that is substantially along the bisection of the two threads accompanied by a motion up or down along the axis of the tip. In some embodiments this motion terminates with an upward motion that disengages the tip from the flosses. In some embodiments, a substantial mirror image of this motion may be performed starting from the other side of the crossing point. Some embodiments may comprise motion of a zig-zig, helical, or elliptically helical nature.
Some cleaning methods in accordance with embodiments of the present invention may comprise one or more of:
Some embodiments of cleaning stations employ a motor to rotate drum 7004 to advance the floss. Some embodiments employ motion of the traverse to advance the floss. In embodiment 7000, elements 7012 are teeth of a cog that is actuated by a traverse-mounted feature 7014 via a traverse motion, e.g., 7016.
Some embodiments of cleaners may be arrayed so that different cleaning systems of fibers, surfaces, liquids, and compositions may be applied.
Some embodiments rely in part on a tip station that ‘normalizes’ a tip's contents. As used herein ‘normalized’ contents may be amenable to reliable processing. Some attributes of normalized contents may be: a high state of mixedness, a substantial lack of internal bubbles, droplets, and secondary menisci, and a substantially known axial position within a tip. Some embodiments of tip stations may perform a partial normalization.
Some embodiments improve normalization within a tip by drawing liquid up to a barrier that passes gases but not liquid, such as a barrier filter. Some embodiments perform normalization by passing the tip contents once or multiply through one or more membranes or meshes within a tip that selectively retains a liquid or a gas. Some mesh/membrane embodiments comprise a surface having one or more of a low surface energy, hydrophobicity, hydrophilicity.
Some embodiments employ the flow controller or a tip station to draw a partial vacuum to expand bubbles so they can rise under gravity. Some embodiments employ centrifugation to separate gas and liquid phases.
Some embodiments of centrifugal tip stations according to the present invention comprise a station that bends a tip either during the process of insertion into the rotating head of the station or at a later stage. Some embodiments of centrifugal tip stations comprise a rotating head that can change geometry so the tip can be inserted and removed without a bend, but centrifugation performed with a bent geometry in such a way that liquid pools under centrifugation at an interior point in the tip. Some embodiments employ centrifugal force to produce a bend in the tip. Some embodiments comprise an interference such that a tip buckles under axial pressure into a curved shape for centrifugation.
Some alternative embodiments of centrifugal tip stations comprise a station that collects liquid at the actuator port or barrier filter or reagent port of a tip. Some such embodiments may require a tip plug at the reagent port or tip cap at the actuator port to eliminate leakage.
Some embodiments of the present invention comprise a tip station wherein a tip experiences a linear or circularly polarized transverse vibration. In some embodiments vibration is driven substantially near the tip reagent port such that the tip experiences a high or maximal vibrational acceleration. Some embodiments apply vibration at an interior point or at the actuator port side of the pipette tip. Some embodiments apply vibration forcing at a plurality of positions.
In some embodiments, this vibration may produce one or more fluid transport effects. Vibration and flexure of menisci produce a flow that can exhibit turbulent mixing at substantially lower Reynolds numbers than would be expected for a single-phase flow, so the vortexer/vibration stage may be an excellent fast mixer and be used to resuspend particles, beads, macromolecules, etc.
Vibration, coupled with the tapering geometry of the tip may produce transport up the pipette tip via unbalanced normal forces.
Vibration amplitude gradients may produce a second-order force that drives fluid away from regions of large vibration intensity, since the overall kinetic energy of a liquid/gas mixture is minimized when the dense liquid undergoes low-intensity vibrations compared to those of the gasses. Such transport may be engineered by: tip design, design of one or more rigid/semirigid mounts, and design of one or more vibration dampers within the vibration station.
Some embodiments of such vibration dampers may comprise a rigid, elastic, semi-compliant, viscoelastic, or non-Newtonian object shaped to interfere with a component of the vibrational motion of the pipette tip. Some dampers may extend annularly around the tip. Some dampers contact the tip asymmetrically. An asymmetric damper may be engineered produce a variation of circular, elliptical, and linear vibration polarization and amplitude along the axis of the tip. Some embodiments of dampers comprise a rubber piece between 0.2 and 5 mm thick, preferably 0.5 to 4 mm, positioned to interfere with the static (non-vibrating) tip by −5 mm to 5 mm, preferably −2 to 2 mm on one edge, located roughly at the top of the desired fluid plug level. Some embodiments may provide for moving a damper as needed during run time to accommodate different liquids and volumes. Some embodiments may comprise a plurality of dampers disposed at different heights from the tip bottom, located at different positions such that the damper that engages with the tip can be selected by offsetting the tip mount in the direction of the desired damper. Some embodiments comprise a helically disposed damper whose engagement can be continuously adjusted by offsetting the tip mount.
Some vortexer/vibration stage embodiments may employ run-time optimization of vibration amplitude, frequency, ramp up, ramp down, degree of damping, and flow control. The degree of damping may be adjusted in some embodiments by moving the tip mount to increase or decrease an interference with a damping element.
A circularly polarized vibration may set up a circumferential rotation of the fluid. Above a threshold rate, the circumferential rotation may produce a fluid profile having a gas-filled hollow core. The presence of this core may allow liquid segments to merge at relatively low vibration levels. The collapse of this core may be controlled by controlling the damping or ramp-down rate of the vibration to allow the collapse of the core to proceed from one end of the annulus to the other without re-entrapping gas pockets.
Some embodiments of vibration producers in accordance with the present invention comprise one or more of: a motor, a solenoid, an ultrasonic transducer, a voice coil, an acoustic horn. Circularly or elliptically polarized vibrations can be produced by a plurality of synchronized linear vibration sources. Some embodiments produce circularly polarized vibrations via a motor-driven stage having an eccentric tip interface.
The eccentric tip interface in some embodiments may further comprise a tapered lead-in that guides the tip to the center. Such an arrangement may have the advantage of bending the tip end into the interface without knowledge of the rotation angle of the motor shaft. A further benefit may be that the tip may be inserted while the motor and eccentric tip is in motion, allowing the motor to be started before the tip is inserted, which may prevent stall or excessive starting current.
Some embodiments further comprise a ball bearing or bushing between the tip and the eccentric interface. Some embodiments comprise interfacing the eccentric stage to a tip having an end plug. Some such embodiments may protect the tip from abrasion during insertion into the stage. Some such embodiments may further protect against the potential for contamination by aerosolization of the tip contents.
A method for normalization of the contents of a tip may comprise one or more of:
In some embodiments it may be preferred not to allow the fluid to come into contact with a barrier filter. In some such embodiments, a lower initial speed ramp-up rate and maximum speed may be desirable. In some embodiments the ramp-down rate may be designed to allow time for an annular plug of fluid to collapse to a solid plug substantially without capturing gas bubbles.
Some embodiments of processing stages may employ a vibrationally induced circumferential flow to drive a secondary flow via interior features, such as ridges, dips, helices or bends of the tip. For example, opposed helices could work to drive plugs of fluid together or apart depending on the rotation sense.
Some embodiments of vibrational stages may employ vibrationally induced circumferential flow to drive one or more of: mixing, degassing, removing bubbles, an axial channel flow from one port of a flexible tube to a second port of a flexible tube. Some embodiments may produce the flow via one or more helically disposed ridges or grooves on the inner surface of the tube. Some embodiments may distort the inner surface of the tube by external forces to produce a helical, varicose, or ratcheting internal geometry. Some embodiments may superimpose a vibrating force on a static shape-producing force to induce axial motion with a channel. Some embodiments may externally induce a travelling wave pattern on the inner surface of a channel to induce the motion.
Some embodiments of the present invention further comprise a thermally controlled reactor station.
Some embodiments establish the compliance of the heat coupler by one or more of: material selection, patterning features into the heat coupler, using a putty-consistency heat coupler. Some embodiments of heat spreaders are thermal interface materials as known in the art, especially, castable, two-part rubber-based filled elastomers.
Some embodiments of thermocyclers comprise an insulator 9108. Some embodiments of insulators are closed-cell foams, such as a polyurethane foam, an aerogel, or conventional insulator as known in the art.
Some embodiments comprise a thermal sensor 9110 proximal to the tip. Some embodiments comprise a thermocouple junction wrapped in a fine “magnet wire” or the like around a tip cavity mold prior to casting of the heat spreader.
In embodiment 9100, a removable tip seal (9010) is inserted into an opening in the shell (9006) and held in place via ‘bayonet’ mounting features 9112. When a tip is inserted the reagent port passes without contacting any external surface into a cavity 9114. A ring seal at 9116 minimizes the loss of tip contents during thermal cycling and seals the end of the tip against pressure generated by temperature changes and gravity. If the tip is unmounted during a reaction, excess pressure may be vented through the tip cap. Having a barrier filter that is outside the heat zone may discourage evaporative loss of sample. Some embodiments may further comprise a septum, valve, or seal at the actuation port to prevent evaporation or other unwanted transport.
Some embodiments of thermocyclers do not have element 9010. Some rely on a tip having a temporary seal in place. Some rely on having the tip connected to a pressure regulator or flow controller.
Some embodiments of thermocyclers according to the present invention may provide tip temperatures between −10° C. and 150° C. Some embodiments of thermocyclers may be used for thermal fractionation, crystallization, phase-change processing, incubation, polymerase chain reaction, in-vitro transcription, labeling, capping, and other physical, chemical, biological, and biochemical processing as known in the art.
Some embodiments of the present invention further comprise a magnetic separator station wherein a tip's contents are moved relative to a non-uniform magnetic field via one or more of: motion of a tip induced by a motion stage, motion of the contents of the tip induced by a flow controller, motion of a magnet or modulation of a field.
Element 10110 is a plug of particles collected on the inner surface of the tip. During elution and collection of the particles, the contents of the tip may be moved axially (10112) by the flow controller.
This may reduce magnetic particle collection times, improve collection efficiency, overcome adverse effects of trapped bubbles, etc. Once the top meniscus 10114 is lowered past the plug of particles, surface tension may retain the plug of particles to the tip surface along with residual liquid. This residual liquid may contain unwanted components that may need to be diluted by repeating an infusion/resuspension/reseparation procedure until a desired purity is reached.
A method for magnetic separation according to the present invention is one or more of:
Some embodiments of the present invention comprise a method containing one or more of the following steps to produce a normalized plug containing a mixture of a plurality of liquids.
buffer, respectively;
Some embodiments of the present invention comprise a station wherein a tip may be sealed and a station where a tip may be unsealed. In some embodiments, these stations may be combined into a single station having shared components, but this arrangement is not intended to be limiting. As used herein, ‘sealing’ and ‘unsealing’ may refer to a process of adding or moving material to block fluid transport and removing or moving material to enable fluid transport, respectively. In contrast, a plug as used herein is characterized as a discrete physical body, however, the distinction is purely semantic and not intended to be limiting. A tip may be sealed by application of a phase-change material, such as a wax. In some embodiments, a tip may be impulse heat sealed closed and impulse heat re-opened. In some embodiments re-opening may employ a different mechanism than heating, e.g., abrasion, cutting, drilling etc.
As used herein, a tip is ‘plugged’ or ‘unplugged’ by physically inserting and removing a body inside or around the tip. Some embodiments of plugs may be used once to avoid cross contamination. Some embodiments of plugs may be decontaminated. Some means of decontamination comprise chemical decontamination, washing, cleaning, auto-claving, pyrolysis, etc., and combinations thereof as known in the art.
Element 12010 is a lever/spring that is switchable between a plug-unretained and plug-retained state. In this embodiment, this switching involves moving a slot between a wide region 12012 and narrow diameter region 12014 through which a plug cannot pass. This motion may be activated via a side force at position 12016, e.g., via a side force from a tip 1002, a side force from a traverse-mounted object, etc. In some alternative embodiments, an alternative mechanism may be employed to produce a switchable retained/un-retained state. In some embodiments a magnetic, an electromagnetic, an electrostrictive, magnetostrictive, hydraulic, pneumatic, etc. actuator may be used actively to switch between a retained and unretained state, as known in the art.
In some embodiments, the mobile microfluidic element may comprise a vial. In some embodiments a vial may further comprise a storage cap as known in the art. In some embodiments, a vial may further comprise a transportation interface. In some embodiments, a vial may further comprise an insulating cap. An objective of a transportation interface for a vial may be to allow a vial to be positioned using a traverse from a one mount to another, including mounts within stages that have a deep recess, e.g., a freezer or ultra-freezer module.
Some embodiments of the present invention comprise a freezer or ultra-freezer apparatus.
In some embodiments, element 14120 is a cast thermal-interface material as known in the art. In some embodiments this material is compliant.
A fragile-sample thawing method of the present invention may comprise one or more of:
A freezing method of the present invention may comprise one or more of:
This application claims priority to U.S. Provisional Application No. 63/328,125, filed Apr. 6, 2022, the entire contents of which are hereby incorporated by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63328125 | Apr 2022 | US |
