Abstract: The present disclosure provides devices, systems, methods for processing and/or analyzing a biological sample. An analytic device for processing and/or analyzing a biological sample may comprise a moving carriage. The analytic device may be portable. The analytic device may receive instructions for performing an assay from a mobile electronic device external to a housing of the analytic device.

Abstract: Embodiments described herein generally provide for the expansion of cells in a cell expansion system using an active promotion of a coating agent(s) to a cell growth surface. A coating agent may be applied to a surface, such as the cell growth surface of a hollow fiber, by controlling the movement of a fluid in which a coating agent is suspended. Using ultrafiltration, the fluid may be pushed through the pores of a hollow fiber from a first side, e.g., an intracapillary (IC) side, of the hollow fiber to a second side, e.g., an extracapillary (EC) side, while the coating agent is actively promoted to the surface of the hollow fiber. In so doing, the coating agent may be hydrostatically deposited onto a wall, e.g., inner wall, of the hollow fiber.

Abstract: The present invention relates to a mixing system for a bioreactor, comprising a plurality of supply units (10), each being able to hold media for use in a bioreactor a mixing unit (30) for creating a uniform mixing of media a first feeding mechanism (20), arranged to feed media from the supply units (10) into the mixing unit (30), a control unit (40) operatively connected to the first feeding mechanism (20) and the mixing unit (30), said control unit (40) being configured to control the first feeding mechanism (20) to feed predetermined amounts of media from the plurality of supply units (10) to the mixing unit (30), and further being configured to control the mixing unit (30) to create a uniform mixing of media. The invention also relates to a method for mixing media for use in a bioreactor.

Abstract: A single-use chamber comprising a primary subchamber containing at least one primary component configured to perform an operation comprising at least one of generation and handling of a biological material; and a secondary subchamber containing at least one of a connection to equipment external to the single-use chamber and a secondary component, wherein the external equipment and the secondary component are configured to support the operation of the at least one primary component; wherein the primary subchamber and the secondary subchamber are configured to be connected to each other so that the at least one primary component is operatively coupled to at least one of the connection and the secondary component.

Abstract: Provided herein are systems, devices, and methods for improved treatment of tissue, such as brain tissue. The improved treatment described herein can result in improved tissue penetration of various compounds and chemicals, such as stains and immunohistochemistry reagents. For example, provided herein is a pressurizing device that may include a chamber body having an opening in one of a top and a sidewall of the body, and may also include a chamber lid covering the opening and releasably coupled to the chamber body proximate the opening. The chamber lid and chamber body form an air-tight cavity. The pressurizing device may also have an inlet passing through one of the chamber body and the chamber lid and into the air-tight cavity. The device may also include a retainer coupled inside the air-tight cavity and configured to releasably couple to at least one tissue sample receptacles.

Abstract: A cell culture monitoring system includes measuring units housed in an incubator and each equipped with an indicator, the measuring units each measuring a state of cells in a culture container mounted therein; and an administration unit. The administration unit includes a receiver that receives, from each of the measuring units, a state of the cells measured, the state being associated with identification information of the measuring unit; an analyzer that analyzes the state of the cells and computes information indicating a culture state; a storage that stores, in association with each other, the information indicating the culture state and the identification information; a display that displays, in association with each other, the information indicating the culture state and an identification based on the identification information; and a controller that controls the indicators so that each of the indicators displays the identification corresponding to the identification displayed on the display.

Abstract: Digester (1) having an agitating device (10) and an agitating device (10) and a method for manufacturing an agitating device (10), the agitating device (10) comprising multiple agitator blades (21-29) which agitator blades (11-13) comprise a plurality of blade sections (21-29) angled relative to one another. The blade sections (21-29) of the agitator blade (11-13) are angled relative to one another such that the agitator blade gradient (11-13) decreases with the distance (30) from a central rotational axis (19) increasing to configure the agitator blade in a flow-optimized three-dimensional shape.

Abstract: Provided are cell culture apparatus and method. The cell culture apparatus comprises a culture column and a perfusion system, the culture column comprising a first and a second tube-connecting caps and a support for cells to attach and grow thereon. The first and the second tube-connecting caps are respectively provided with a perfusion inlet and a perfusion outlet; The perfusion system comprises a culture medium storage device, a perfusion tube and a perfusion pump. A complete and closed culture column is formed in the cell culture device after the cells are inoculated, and the culturing is completed by the perfusion system to avoid contamination.

Abstract: A compact culture device capable of performing large-scale culture in an aseptic state. A culture device has a culture bag which has ports through which a liquid flows and enables cell culture, a bag holding portion having holding plates holding the culture bag and rotating shafts, a rotation mechanism supporting and rotating the rotating shaft, a liquid supply/discharge mechanism supplying and discharging a liquid to/from the culture bag, and a rotation control portion controlling the rotation of the rotation mechanism.

Abstract: A method of preparing reagents includes inserting a cartridge into an instrument. The cartridge includes a plurality of reagent enclosures disposed in a cavity of the cartridge and exposing a port to an exterior of the cartridge. Each reagent enclosure includes a reagent container including a reagent and an internal cavity defining a compressible volume, an opening defined through the reagent container to the internal cavity. The method further includes connecting a plurality of fluid ports to the openings of the plurality of reagent enclosures; applying a solution through the fluid ports to at least partially fill the plurality of reagent enclosures; and cycling a pressure of the cavity, whereby for each of the reagent enclosures, during increasing pressure, the solution enters the internal cavity of the reagent container, combines with the reagent, and compresses the compressible volume, and during decreasing pressure, the compressible volume decreases and the reagent is ejected through the opening.

Abstract: A liquid substrate tank for a biogas plant includes an interior fillable with a liquid substrate and a bottom wall defining the interior on the bottom and being particularly at least regionally flat. A trough-shaped recess extending over a partial region of the bottom wall is formed in the bottom wall, to which and/or into which recess an extraction line of an extraction device is guided. The extraction device has an open-loop and/or closed-loop control device actuating the extraction device for extracting a substrate/sand mixture accumulating in the recess during operation from the recess and thus from the interior through the extraction line. The extraction device has an accommodation and/or sedimentation tank, or separator, connected to the extraction line relative to flow for accommodating or separating the substrate/sand mixture extracted through the extraction line into substrate and sand phases.

Abstract: Disclosed is a sample analysis system comprising a cleaning liquid preparation apparatus that prepares a cleaning liquid, and a sample analyzer that comprises a measurement unit that measures a sample and a reservoir that stores the cleaning liquid prepared by the cleaning liquid preparation apparatus. The sample analyzer cleans at least a part of the measurement unit with the cleaning liquid. The cleaning liquid preparation apparatus selectively executes a first supply mode to supply the cleaning liquid to the reservoir when a liquid amount in the reservoir reaches a first amount, and a second supply mode to supply the cleaning liquid to the reservoir when the liquid amount in the reservoir reaches a second amount less than the first amount.

Abstract: A dual chamber bioreactor for producing complex, multilayer tissue, organs, organ parts, and skin replacements has been developed. The bioreactor is modular and incorporates a removable tissue culture cassette. By rotating the dual chamber bioreactor along the horizontal axis, different populations of cells with different growth requirements can be cultured on the different surfaces of the tissue culture cassette that are exposed to different media reservoirs. Culturing different populations of cells on different surfaces of the tissue culture cassette enables the production of multilayer tissue and organs. The tissue culture cassette can contain one or more discrete tissue culture sections.

Abstract: A control unit includes a first connector configured to connect a proportional pressure regulator to a positive pressure supply and a second connector configured to connect the proportional pressure regulator to a negative pressure supply. The control unit further includes at least one sensor configured to detect an amount of air flow (volume per unit of time), positive or negative, within an air flow line connected to an output of the proportional pressure regulator, and a third connector configured to connect the air flow line to an air side of a diaphragm. Additionally, the control unit includes a controller programmed to control at least an opening and closing function of the proportional pressure regulator to attain a desired amount of air flow (volume per unit of time), positive or negative, within the air flow line.

Abstract: A method for promoting biological activity uses a filter system to increase cell production of a fed batch bioreactor. The filter system cycles bioreactor fluid through a hollow fiber tangential flow filter which separates metabolic wastes (as well as proteins) from cells produced in bioreactor and returned to fed batch bioreactor, improving cell production in the fed batch bioreactor. The filter system includes a disposable pump and filter, and a reusable control system. The pump is a low shear gamma stable pump gently cycling bioreactor fluid through the filter with minimal damage to the cells produced in the bioreactor. The pumphead and hollow fiber tangential flow filter are disposable. The pump motor is part of the control system and is reusable. The pumphead and filter are provided as an assembled and pre-sterilized unit allowing simple and quick attachment to the fed batch bioreactor, and simple and quick disposal.

Abstract: The present invention relates to methods for amplifying nucleic acids in micro-channels. More specifically, the present invention relates to methods for performing a real-time polymerase chain reaction (PCR) in a continuous-flow microfluidic system and to methods for monitoring real-time PCR in such systems.

Abstract: The invention relates to a container, in particular a fermenter for a biogas plant, wherein in the container a mixer is arranged that can be removed through an inspection opening provided in a container wall. A boom is provided for this purpose. Furthermore, the invention relates to a related method and a related use.

Abstract: A microclinical analyzer usable for analysis of one or more bio-objects, each bio-object including an organ or a group of cells includes a fluidic network having a plurality of fluidic switches, a plurality of fluidic paths in fluid communication with the plurality of fluidic switches, and one or more on-chip pumps coupled to corresponding fluidic paths; a sensor array coupled to the fluidic network; and a microcontroller for individually controlling the plurality of fluidic switches and the one or more on-chip pumps of the fluidic network as so to operably and selectively deliver an effluent of at least one bio-object to the sensor array for detecting properties of the effluent, or to a predetermined outlet destination.

Abstract: Microfluidic devices and methods for perfusing a cell with perfusion fluid are provided herein, wherein the gravitational forces acting on the cell to keep the cell at or near a retainer or a retaining position exceed the hydrodynamic forces acting on the cell to move it toward an outlet. Also provided, are methods for assaying cell products within the microfluidic device.

Abstract: A manufacturing device and a manufacturing method of a test strip. The manufacturing device includes a fluid push module, a fluid flow module and a fluid output module. The fluid push module includes an actuator and a transmission unit. The transmission unit has at least a fluid delivery member. The fluid flow module includes a reagent storage unit and a reagent delivery unit. The reagent storage unit has at least one reagent storage chamber. The reagent delivery unit has at least one drain chamber, at least one first infusion line, at least a second infusion line and a plurality of check valves. The fluid output module includes a plurality of reagent outlets and a reagent output unit, and one end of each of the reagent outlets is configured with an inner recess. The reagent output unit has a plurality of channels corresponding to the reagent outlets.

Abstract: Provided is a microfluidic device, having at least one fluid compartment, an aerator, at least one connecting tube, and a peristaltic pump. The at least one fluid compartment has a base frame, a culture layer, and a flow layer. The culture layer has a base layer and an intermediate layer, and the intermediate layer has at least one opening formed through the intermediate layer to form at least one culture chamber. The flow layer has a top frame layer, a fluid layer, and a transparent layer. The top frame layer has two channels and a hollow. The fluid layer has at least one fluid chamber which communicates with the at least one culture chamber of the culture layer. The at least one connecting tube connects the two channels of the top frame layer of the fluid compartment, the aerator, and the peristaltic pump.

Abstract: A filtration assembly including: i) a hyperfiltration assembly including: a high pressure vessel including a feed port, concentrate port and permeate port, and a plurality of serially arranged spiral wound hyperfiltration membrane modules; ii) a bioreactor assembly including: a plurality of spiral wound bioreactors each comprising a flat sheet having two opposing bio-growth surfaces and a feed spacer spirally wound about an axis (Y); and iii) a fluid flow pathway adapted for fluid connection with a fluid feed source and extending in a parallel flow pattern through the bioreactors, and subsequently into the feed port of the high pressure vessel, successively through the spiral wound hyperfiltration membrane modules in a serial flow pattern and out of the concentrate port and permeate port.

Abstract: Disclosed herein are bioreactor systems and methods of utilizing said systems.

Abstract: An apparatus for producing an organic or organo-mineral fertilizer includes —a main tank receiving water, —a reactor providing cavitation and magnetic field for activating water or for treating a biological suspension, —a mixing tank containing a preliminary shredder, —an injector receiving and saturating the suspension with air, —a fermenter receiving the obtained mixture and creating a volumetric liquid-air flow passed therethrough and fermented by biological humus. The suspension is filtered and passed into a clearing tank. At predetermined conditions, the apparatus carries out a method encompassing a preliminary treatment of water in a looped circuit by connecting the main tank with the reactor via a pump. The activated water is supplied to the mixing tank added with preliminary shredded humus. The circuit is reconnected to further treat the suspension, finally shred its particles, supply it to the fermenter, additionally mix it with humus, filter it and thereby obtain the fertilizer.

Abstract: A fluidic device holder configured to orient a fluidic device. The device holder includes a support structure configured to receive a fluidic device. The support structure includes a base surface that faces in a direction along the Z-axis and is configured to have the fluidic device positioned thereon. The device holder also includes a plurality of reference surfaces facing in respective directions along an XY-plane. The device holder also includes an alignment assembly having an actuator and a movable locator arm that is operatively coupled to the actuator. The locator arm has an engagement end. The actuator moves the locator arm between retracted and biased positions to move the engagement end away from and toward the reference surfaces. The locator arm is configured to hold the fluidic device against the reference surfaces when the locator arm is in the biased position.

Abstract: Cartridge-based thermocyclers can include cartridges that are configured to move a fluid between distinct chambers. In some cases, the cartridge-based thermocyclers can be used for thermocycling a sample fluid comprising a deoxyribonucleic acid (DNA) target to perform polymerase chain reaction (PCR). Individual chambers can be heated, cooled, and/or compressed to mix fluid within the chamber or to propel fluid in the chamber into another chamber. The cartridges can have a laminate construction. The cartridges can be configured to enable multiplexed thermocycling and/or detection.

Abstract: A system for culturing a photosynthetic organism such as a microalga has a liquid storage vessel for storing a liquid that absorbs more light in a short-wavelength range than light in a long-wavelength range, a culture vessel for storing a culture solution containing a photosynthetic organism to be cultured and disposed in the liquid storage vessel, a light quantity measuring unit for measuring the quantity of light that the culture vessel receives and a liquid depth controlling unit for controlling the liquid depth from the surface of the light-absorbing solution to the culture vessel based on the measurement result of the light quantity measuring unit. The light quantity measuring unit measures quantities of light which the culture vessel receives separately for different wavelength ranges.

Abstract: A microorganism culture device and a method of using the device. The device includes an open chamber, wherein microorganisms are likely to be deposited within a liquid for subsequent study. The open chamber simplifies the deposition of the microorganisms. The chamber is further provided with retention features, whereby microorganisms can be retained therein. In addition, the device includes an overflow area, wherein capillary structures are configured to retain excess liquid overflowing from the open chamber, e.g. when covering the device with a cover. As such, it allows for confining microorganism in the chamber, while excess fluid is captured externally, e.g. to seal the device with a cover.

Abstract: A closed system for rehydrating powder and delivering the rehydrated powder to a reactor, may include a liquid reservoir for containing liquid; a syringe configured to contain powder to be rehydrated; a reactor; a controller for controlling operation of the syringe; and a conduit fluidically linking the liquid reservoir to a port of the syringe, fluidically linking the port to the reactor. The controller is configured to operate the syringe so as to draw liquid from the liquid reservoir into the syringe and rehydrate the powder, or to drive the rehydrated powder into the reactor.

Abstract: In one aspect of the invention, an integrated bio-object microfluidics chip includes a fluidic network having a plurality of inlets for providing a plurality of fluids, a plurality of outlets, a bio-object chamber for accommodating at least one bio-object, a plurality of fluidic switches, and one or more pumps, coupled to each other such that at least one fluidic switch operably and selectively receives one fluid from a corresponding inlet and routes the received fluid, through the one or more pumps, to the bio-object chamber so as to perfuse the at least one bio-object therein, and one of the downstream fluidic switches selectively delivers an effluent of the at least one bio-object responsive to the perfusion to a predetermined outlet destination, or to the at least one fluidic switch for recirculation.

Abstract: The invention relates to a system of fluidic valves and pumps and associated fluidic channels integratable into a bio-object microfluidics module. The module includes input and output buses; upstream and downstream interconnection bus control valves (CVs) coupled to the input and output buses, respectively. It may include arterial, venous, wash and waste bus lines, each connecting between the upstream and downstream interconnection bus CVs. It may also include an input CV connecting to the arterial bus line, upstream interconnection bus CV, bio-object and inlets, and an output CV connecting to the bio-object, input CV, downstream interconnection bus CV and outlets; and a pump connecting between the input CV and bio-object. The system can be arranged to provide MicroFormulator functionality enabling precise mixtures of drugs, chemicals, or biochemicals to be delivered in a time-dependent fashion to biological entities housed in individual wells or chambers.

Abstract: A method for extracting stem cells from a non-embryonic stem cell source, including providing a non-embryonic stem cell source including stem cells; perfusing the non-embryonic stem cell source with a pulsatile flow of a perfusion solution to produce a perfusate including stem cells and a perfused non-embryonic stem cell source; and isolating the stem cells from the perfusate to produce isolated stem cells, is provided. Also provided is a non-embryonic stem cell line derived from a non-embryonic stem cell obtained using the pulsatile perfusion extraction method.

Abstract: Devices and methods are provided for removing media from a culture vessel that decreases disruption of the interface between the cellular material and media within the vessel such that aspiration and removal of cells or cell clusters along with the media is minimized. In addition, the media fluid turbulence is decreased so as to minimize the activation or disruption of cells and cell clusters.

Abstract: The cultivation, by optimized growth and harvesting of algae derived bio-mass may provide useful feedstock for various products and processes. The present invention provides an apparatus that allows for the optimized growth and harvesting of algae within a photo-bioreactor. The photo-bioreactor may include a channel and a propulsion unit for circulating an algae mixture through a channel while exposing the algae mixture to light to support photosynthesis and growth of the algae. A method is also provided for the optimizing the growth and harvesting of algae utilizing a number of different input streams. Further, a system including a programmable control assembly is provided for the growth and harvesting of algae.

Abstract: A device for performing a cell study. The device comprises a plate having a plurality of wells, each configured for containing aqueous solution and having a well bottom with a plurality of picowells and a plurality of biosensors each configured for measuring at least one cell characteristic while being in contact with the aqueous solution in a respective the well. The position of each the biosensor in a respective the well is limited by at least one pin.

Abstract: A microfluidic device platform may include a valve manifold adapted to deliver a programmable pressure to a plurality of ports, a cell chamber having programmable environmental control, and a chip-to-world interface.

Abstract: The present invention, provides a flow cytometry apparatus for the detection of particles from a plurality of samples comprising: means for moving a plurality of samples comprising particles from a plurality of respective source wells into a fluid flow stream; means for introducing a separation gas between each of the plurality of samples in the fluid flow stream; and means for selectively analyzing each of the plurality of samples for the particles. The present invention also provides a flow cytometry method employing such an apparatus.

Abstract: The present invention provides a method and apparatus for tissue, such as an allograft, storage and preservation for extended periods of time at room temperature in a sterile tissue culture chamber. The invention further provides a process for maintaining the sterility of tissue using the apparatus as described.

Abstract: This invention provides for the efficient positioning of a sample to be analyzed by using either magnetic or electro-mechanical fields to retain the sample in the ionization region. In an embodiment of the present invention, the sample is contacted with a sampler device, which is inserted into a chamber and accurately positioned using electro-mechanical devices. In an embodiment of the invention, the influence of an electro-mechanical field on the sampler device enables the sample to be positioned in the ionization region to be contacted by particles that result in ionization of the sample whereby rendering the resulting ions available for analysis.

Abstract: An autonomous monitoring system for monitoring for bioagents. A collector gathers the air, water, soil, or substance being monitored. A sample preparation means for preparing a sample is operatively connected to the collector. A detector for detecting the bioagents in the sample is operatively connected to the sample preparation means. One embodiment of the present invention includes confirmation means for confirming the bioagents in the sample.

Abstract: Systems and methods of sample processing and temperature control are disclosed. The invention may especially relate to temperature control, and may in some embodiments be methods of temperature control of an automated sample processing system and methods of automated sample processing. Specifically, the present invention provides temperature control in relation to sample processing systems and methods of processing samples, and in some embodiments provides temperature control in relation to sample carriers and processing materials such as reagents. Corresponding systems and devices are disclosed, including sample processing systems (1), sample carrier temperature regulation systems (60), reagent temperature regulation systems, sample processing control systems, and temperature regulation devices, among other embodiments.

Abstract: Devices and methods are provided for reducing matrix effects in protein precipitated bioanalytical samples comprising: a support, and a sorbent associated with the support capable of binding matrix interfering agents present in the bioanalytical sample, wherein the device further comprises filtering means for removing precipitated protein particles. The filtering means is a size exclusion filter or a polymeric or inorganic monolith having a maximum pore size less than or equal to the diameter of the particles to be removed from the sample, and can be integral with the sorbent or associated with the sorbent. The sorbent is characterized by sufficient selectivity between the matrix interfering agents and analytes of interest to provide retention of the matrix interfering agents while providing elution of the analytes of interest (e.g., a reversed phase or a polar modified reversed phase).

Abstract: A microfluidic hanging drop chip is disclosed. Also disclosed are methods for culturing cells and forming cell aggregates in hanging drops.

Abstract: The present invention discloses a sperm selecting system and the method thereof. The brief concept of the present invention is to generate a flow field by hydraulic pressure difference then utilize the property that the sperm swims against the flow field so as to difference the sperms by vitality thereof. One of the main features of the present invention is that the sperms be selected are initially set at the entrance of the flow field instead of the exit of the system. Furthermore, an activating design can be selectively added to the present invention so as to activate the sperm be affected by the process of freeze storing.

Abstract: An automated on-touch template bead preparation system is provided and includes a membrane-based emulsion generation subsystems, an emulsion PCR (ePCR) thermocycling plate and subsystem, and a continuous centrifugation emulsion breaking and templated bead collection subsystem. The emulsion generation subsystem provides uniformity in the preparation of an inverse emulsion and may be used to create large or small volume inverse emulsions rapidly and reproducibly. An emulsion-generating device is provided that can supply a continuous stream of an inverse emulsion to a thermocycling subsystem, in automated fashion. The ePCR subsystem can continuously thermocycle an inverse emulsion passed therethrough and includes static temperature zones and a consumable thermocycling plate. The continuous centrifugation subsystem can continuously break a thermally cycled inverse emulsion and collect template beads formed in the aqueous microreactor droplets of the inverse emulsion.

Abstract: An organic waste processing system and method for producing an organic waste slurry for the production of bio-gas, transportation fuels or chemical products, wherein the system and method produces an organic waste slurry having substantially ten to fifteen percent in total solids and high levels of COD.

Abstract: A microfluidic device for controlled encapsulation of particles of sub-millimetric dimensions, or clusters of such particles, the device comprising: a first duct for delivering a first liquid phase containing particles for encapsulating in suspension; a second duct for conveying a flow of a second liquid phase that is immiscible with said first liquid phase; the first duct opening out into the second duct and forming a fluidic junction therewith; at least one microfluidic duct for discharging the first liquid phase flowing in said first duct and provided with a mouth located upstream from said junction and liable to be obstructed, at least in part, by a particle in suspension, thereby causing pressure to rise in the first duct. The invention also provides a microfluidic system including such a device, and a method of encapsulation based on using such a device.

Abstract: A cell expansion system includes an air removal chamber to provide a bubble trap so that air and/or gas bubbles do not enter the bioreactor of the cell expansion system. The air removal chamber includes a pair of ports situated at the bottom of the air removal chamber. An entrance port allows fluid to enter the air removal chamber, and an exit port allows fluid to exit the air removal chamber. In one embodiment the air removal chamber forms an element of a premounted fluid conveyance assembly for use with a cell expansion machine.

Abstract: This invention relates to stable non-aqueous single phase viscous vehicles and to formulations utilizing such vehicles. The formulations comprise at least one beneficial agent uniformly suspended in the vehicle. The formulation is capable of being stored at temperatures ranging from cold to body temperature for long periods of time. The formulations are capable of being uniformly delivered from drug delivery systems at an exit shear rate of between about 1 to 1×10?7 reciprocal second.

Abstract: A dispensing unit that sucks and discharges a blood specimen via a nozzle. A liquid level-measuring unit that measures the liquid level height. A serum volume-estimating unit that estimates the volume of the serum separated in the blood specimen, on the basis of the total blood volume, said total blood volume corresponding to the volume of the blood specimen and having been derived from the liquid level height, and a hematocrit value. A residual volume-estimating unit that calculates the volume of the serum remaining after suction, on the basis of the serum volume estimated by the serum volume-estimating unit and the volume of the serum that is going to be sucked by the dispensing unit. A controller that controls the suction procedure of the dispensing unit so that the estimated residual volume is not less than the desired volume of the serum to be left in the blood collection tube.