Isolation tube with a rheological control member and a plunger
Inventors
Walsh, John D. • Ronsick, Christopher S. • Wilson, Mark S. • Ririe, Kirk • Hill, Ryan T.
Assignees
Biomerieux Inc • Biofire Defense LLC
Publication Number
US-11305273-B2
Publication Date
2022-04-19
Expiration Date
2038-07-26
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Abstract
A separation container for extracting a portion of a sample for use or testing and method for preparing samples for downstream use or testing are provided. The separation container may include a body defining an internal chamber. The body may define an opening, and the body may be configured to receive the sample within the internal chamber. The separation container may further include a seal disposed across the opening, such that the seal may be configured to seal the opening of the body, and a plunger movably disposed at least partially inside the internal chamber. The plunger may be configured to be actuated to open the seal and express the portion of the sample.
Core Innovation
The invention provides a separation container for extracting a portion of a sample for use or testing, which includes a body defining an internal chamber, a seal disposed across an opening in the body, and a plunger movably disposed at least partially inside this internal chamber. The plunger is configured to open the seal and express a portion of the sample, and may be configured to pierce the seal and thereby enable fluid communication from the internal chamber to the area outside the body. The separation container may further include a rheological control member within the internal chamber to reduce or prevent mixing between sample and a density cushion.
The problem addressed by this invention, as described in the background section, is that existing sample preparation devices for separating microorganisms from sample material—such as blood samples—require multiple steps (lysing, washing, decanting, spinning) often performed in different containers and with high dependence on user skill, leading to lower consistency, increased risk of contamination, and potential hazardous exposure. Additionally, handling varied microorganism types complicates achieving reliable pellet properties and maintaining the viability necessary for downstream testing.
In response, the disclosed separation container system allows for the separation of a sample by centrifugation and subsequent extraction of a pellet using a single device and minimal manual handling. The plunger can be actuated to open the sealed end and express the isolated microorganism pellet, while a rheological control member (such as an annular barrier or floating layer) improves separation efficiency and purity by minimizing undesirable mixing before centrifugation. The system further supports downstream workflows such as resuspension, culturing, or analytical testing directly or with minimal transfer, thus streamlining sample preparation and reducing contamination risk.
Claims Coverage
The patent contains multiple independent claims focusing on the construction and function of a separation container with an integrated plunger and rheological control member for efficient sample extraction.
Separation container with integrated plunger and seal
The separation container comprises a body with an internal chamber and an opening. A seal is disposed across the opening to seal the chamber. A plunger is movably disposed at least partially inside the internal chamber, with a point at a first distal end configured to pierce the seal and enable fluid communication between the chamber and the external environment. The plunger can be actuated to open the seal and express a portion of the sample.
Rheological control member with slideable bore
Inside the internal chamber, a rheological control member is provided. This member includes a bore with a diameter greater than the outer diameter of the plunger, allowing the rheological control member to slide relative to both the plunger and the container wall.
Variable diameter chamber with sealing engagement by plunger
The container body defines an axis from the opening to a second end. The internal chamber narrows from a collection diameter at the second end to a pellet diameter at the opening. The plunger is configured such that at least a portion of it sealingly engages the chamber at the pellet diameter region, and the associated plunger diameter is greater than or equal to the pellet diameter.
Plunger with circumferential plunger seal
On the plunger, a circumferential plunger seal is provided, positioned to sealingly engage the chamber of the body at the pellet diameter region. This configuration divides the internal chamber into two sub-chambers during actuation.
Buoyancy of plunger and rheological control member
The plunger is optionally buoyant in water or density cushion material, enabling it to float upward during centrifugation and avoid premature penetration of the seal. The rheological control member can likewise be buoyant and may float on the sample or density cushion.
Rheological control member positioned for flex-conditioning during centrifugation
The rheological control member can be annularly positioned between the plunger and chamber wall and held at a fixed position by an interference fit. The chamber wall is flexibly deformable so the interference fit is released during centrifugation, allowing the member to float or move, improving separation.
Sample collecting vessel attachment
The separation container optionally includes a sample collecting vessel configured to engage and surround the opening of the body, collecting the expressed sample after the plunger is actuated.
Method for sample preparation and pellet extraction
A method is claimed for preparing samples, involving disposing a sample into the separation container (with integrated plunger and rheological control member), centrifuging to generate a pellet, and expressing the pellet by depressing the plunger to open the seal. The method supports further steps like expressing into a collecting vessel, and is suitable for downstream analyses.
The patent broadly covers a system for sample separation and extraction using a container with a moveable plunger, a pierceable seal, and a rheological control member designed for optimal separation, minimal contamination, and compatibility with downstream processing.
Stated Advantages
Enables separation and extraction of microorganism samples with fewer operational steps and in a single device, eliminating the need for multiple containers or equipment.
Reduces required user training and manual handling, allowing even untrained users to recover a pellet with minimal effort and increased consistency.
Minimizes contamination risk and user exposure, particularly when handling dangerous or pathogenic microorganisms, by enabling sterile operation and limiting sample transfer.
Preserves viability of recovered microorganisms, supporting downstream applications such as culturing, antibiotic susceptibility testing, or phenotypic identification, which are often hindered by harsher separation methods.
Allows use of whole blood and other clinical/non-clinical samples directly, without a need for pre-culturing or extensive sample processing.
Provides a predictable, repeatable process and controlled mechanical pressure for expressing separated pellets, improving recovery and reducing sample loss.
Improves robustness and purity of the separated sample by using a rheological control member to prevent mixing of sample with the density cushion.
Documented Applications
Preparation of clinical and non-clinical samples (e.g., blood, serum, plasma, urine, nasal swabs, foodstuffs, cell cultures) for testing and analysis.
Preparation of viable samples suitable for culturing, antibiotic susceptibility testing (AST), phenotypic identification, and other growth-based downstream applications.
Preparation of samples for identification by mass spectrometry (e.g., MALDI-TOF), nucleic acid amplification techniques, spectroscopy (Raman, FTIR), immunoassay, probe-based assays, agglutination tests, and other analytical procedures.
Processing yeast and bacterial samples from blood cultures for direct ID and AST using larger or small volume separation containers as specified.
Direct use with whole blood, other body fluids, and diverse complex specimen matrices, including veterinary and food testing, without prior culturing.
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