scholarly journals High resolution bacterial separation from blood using elasto-inertial microfluidics

2021 ◽  
Author(s):  
Sharath Narayana Iyengar ◽  
Tharagan Kumar ◽  
Gustaf Måertensson ◽  
Aman Russom
Keyword(s):  
Sample Preparation ◽  
Blood Sample ◽  
Blood Cells ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Unmet Need ◽  
Outer Wall ◽  
Separation Performance ◽  
Label Free ◽  
Inertial Microfluidics

Improved sample preparation has the potential to address a huge unmet need for fast turnaround sepsis tests that enable early administration of appropriate antimicrobial therapy. In recent years, inertial and elasto-inertial microfluidics-based sample preparation has gained substantial interest for bioparticle separation applications. However, for applications in blood stream infections the throughput and bacteria separation efficiency has thus far been limited. In this work, for the first time we report elasto-inertial microfluidics-based bacteria isolation from blood at throughputs and efficiencies unparalleled with current microfluidics-based state of the art. In the method, bacteria-spiked blood sample is prepositioned close to the outer wall of a spiral microchannel using a viscoelastic sheath buffer. The blood cells will remain fully focused throughout the length of the spiral channel while bacteria migrate to the inner wall for effective separation. Initially, microparticles were used to investigate particle focusing and the separation performance of the spiral device. A separation efficiency of 96% for the 1 µm particles was achieved, while 100% of 3 µm particles were recovered at the desired outlet at a throughput (sample + sheath) of 1 mL/min. Following, processing blood samples revealed a minimum of 1:2 dilution was necessary to keep the blood cells fully focus at the outer wall. In experiments involving bacteria spiked in diluted blood, viable E.coli were continuously separated at a total flow rate of 1 mL/min, with a separation efficiency between 82 to 90% depending on the blood dilution. Using a single spiral, it takes 40 minutes to process 1 mL of whole blood at a separation efficiency of 82% and 3 hr at 90% efficiency. To the best of our knowledge, this is the highest bacteria separation efficiency from blood sample reported using inertial and elasto-inertial methods. As such, the label-free, passive high efficiency and high throughput of bacteria isolation method has a great potential for speeding up downstream phenotypic and molecular analysis of bacteria.

scholarly journals High resolution and high throughput bacteria separation from blood using elasto-inertial microfluidics

2020 ◽  
Author(s):  
Sharath Narayana Iyengar ◽  
Tharagan Kumar ◽  
Gustaf Mårtensson ◽  
Aman Russom
Keyword(s):  
Sample Preparation ◽  
Blood Sample ◽  
High Throughput ◽  
Blood Cells ◽  
Separation Efficiency ◽  
Unmet Need ◽  
Outer Wall ◽  
Separation Performance ◽  
Label Free ◽  
Inertial Microfluidics

AbstractImproved sample preparation has the potential to address a huge unmet need for fast turnaround sepsis tests that enable early administration of appropriate antimicrobial therapy. In recent years, inertial and elasto-inertial microfluidics-based sample preparation has gained substantial interest for bioparticle separation applications. However, for applications in blood stream infections the throughput and bacteria separation efficiency has thus far been limited. In this work, for the first time we report elasto-inertial microfluidics-based bacteria isolation from blood at throughputs and efficiencies unparalleled with current microfluidics-based state of the art. In the method, bacteria-spiked blood sample is prepositioned close to the outer wall of a spiral microchannel using a viscoelastic sheath buffer. The blood cells will remain fully focused throughout the length of the channel while bacteria migrate to the inner wall for effective separation. Initially, particles of different sizes were used to investigate particle focusing and the separation performance of the spiral device. A separation efficiency of 96% for the 1 µm particles was achieved, while 100% of 3 µm particles were recovered at the desired outlet at a high throughput of 1 mL/min. Following, processing blood samples revealed a minimum of 1:2 dilution was necessary to keep the blood cells fully focus at the outer wall. In experiments involving bacteria spiked in diluted blood, viable E.coli were continuously separated at a total flow rate of 1 mL/min, with an efficiency between 82 to 90% depending on the blood dilution. Using a single spiral, it takes 40 minutes to process 1 mL of blood at a separation efficiency of 82% and 3 hours at 90% efficiency. To the best of our knowledge, this is the highest blood sample throughput per single microfluidic chip reported for the corresponding separation efficiency. As such, the label-free, passive and high throughput bacteria isolation method has a great potential for speeding up downstream phenotypic and molecular analysis of bacteria.

scholarly journals Combining Electrostatic, Hindrance and Diffusive Effects for Predicting Particle Transport and Separation Efficiency in Deterministic Lateral Displacement Microfluidic Devices

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 126
Author(s):  
Valentina Biagioni ◽  
Giulia Balestrieri ◽  
Alessandra Adrover ◽  
Stefano Cerbelli
Keyword(s):  
Particle Transport ◽  
Separation Efficiency ◽  
Lateral Displacement ◽  
Operating Conditions ◽  
Separation Performance ◽  
Label Free ◽  
Deterministic Lateral Displacement ◽  
Promising Tool ◽  
Label Free Detection ◽  
Diffusive Effects

Microfluidic separators based on Deterministic Lateral Displacement (DLD) constitute a promising technique for the label-free detection and separation of mesoscopic objects of biological interest, ranging from cells to exosomes. Owing to the simultaneous presence of different forces contributing to particle motion, a feasible theoretical approach for interpreting and anticipating the performance of DLD devices is yet to be developed. By combining the results of a recent study on electrostatic effects in DLD devices with an advection–diffusion model previously developed by our group, we here propose a fully predictive approach (i.e., ideally devoid of adjustable parameters) that includes the main physically relevant effects governing particle transport on the one hand, and that is amenable to numerical treatment at affordable computational expenses on the other. The approach proposed, based on ensemble statistics of stochastic particle trajectories, is validated by comparing/contrasting model predictions to available experimental data encompassing different particle dimensions. The comparison suggests that at low/moderate values of the flowrate the approach can yield an accurate prediction of the separation performance, thus making it a promising tool for designing device geometries and operating conditions in nanoscale applications of the DLD technique.

scholarly journals High-Efficiency Plasma Separator Based on Immunocapture and Filtration

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 352
Author(s):  
Xiaosong Su ◽  
Jianzhong Zhang ◽  
Dongxu Zhang ◽  
Yingbin Wang ◽  
Mengyuan Chen ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Blood Sample ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Point Of Care ◽  
Cost Effective ◽  
Plasma Separation ◽  
Centrifuge Method ◽  
Purification Membranes ◽  
Whole Blood Sample

The shortcomings of standard plasma-separation methods limit the point-of-care application of microfluidics in clinical facilities and at the patient’s bedside. To overcome the limitations of this inconvenient, laborious, and costly technique, a new plasma-separation technique and device were developed. This new separation method relies on immunological capture and filtration to exclude cells from plasma, and is convenient, easy to use, and cost-effective. Most of the RBCs can be captured and immobilized by antibody which coated in separation matrix, and residue cells can be totally removed from the sample by a commercially plasma purification membranes. A 400 µL anti-coagulated whole blood sample with 65% hematocrit (Hct) can be separated by the device in 5 min with only one pipette. Up to 97% of the plasma can be recovered from the raw blood sample with a separation efficiency at 100%. The recovery rate of small molecule compounds, proteins, and nucleic acid biomarkers is evaluated; there are no obvious differences from the centrifuge method. The results demonstrate that this method is an excellent replacement for traditional plasma preparation protocols.

scholarly journals High-Throughput, Label-Free Isolation of White Blood Cells From Whole Blood Using Parallel Spiral Microchannels With U-Shaped Cross-Section

2021 ◽  
Author(s):  
Amirhossein Mehran ◽  
Peyman Rostami ◽  
Mohammad Said Saidi ◽  
Bahar Firoozabadi ◽  
Navid Kashaninejad
Keyword(s):  
Cross Section ◽  
High Throughput ◽  
Whole Blood ◽  
Blood Cells ◽  
High Efficiency ◽  
Rectangular Cross Section ◽  
White Blood Cells ◽  
Label Free ◽  
Entire Cross Section ◽  
Shaped Cross Section

Rapid isolation of white blood cells (WBCs) from whole blood is an essential part of any WBC examination platform. However, most conventional cell separation techniques are labor-intensive and low throughput, require large volumes of samples, need extensive cell manipulation, and have low purity. To address these challenges, we report the design and fabrication of a passive, label-free microfluidic device with a unique U-shaped cross-section to separate WBCs from whole blood using hydrodynamic forces that exist in a microchannel with curvilinear geometry. It is shown that the spiral microchannel with a U-shaped cross-section concentrates larger blood cells (e.g., WBCs) in the inner cross-section of the microchannel by moving smaller blood cells (e.g., red blood cells (RBCs) and platelets) to the outer microchannel section and preventing them from returning to the inner microchannel section. Therefore, it overcomes the major limitation of a rectangular cross-section where secondary Dean vortices constantly enforce particles throughout the entire cross-section and decrease its isolation efficiency. Under optimal settings, more than 95% of WBCs can be isolated from whole blood under high-throughput (6 ml/min), high-purity (88%), and high-capacity (180 ml of sample in 1 hour) conditions. High efficiency, fast processing time, and non-invasive WBC isolation from large blood samples without centrifugation, RBC lysis, cell biomarkers, and chemical pre-treatments make this method an ideal choice for downstream cell study platforms.

scholarly journals High throughput viscoelastic particle focusing and separation in spiral microchannels

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tharagan Kumar ◽  
Harisha Ramachandraiah ◽  
Sharath Narayana Iyengar ◽  
Indradumna Banerjee ◽  
Gustaf Mårtensson ◽  
...  
Keyword(s):  
High Resolution ◽  
High Throughput ◽  
Separation Efficiency ◽  
Point Of Care ◽  
Outer Wall ◽  
Reynolds Numbers ◽  
Inertial Microfluidics ◽  
Flow Rates ◽  
Particle Focusing ◽  
Sample Flow Rate

AbstractPassive particle manipulation using inertial and elasto-inertial microfluidics have received substantial interest in recent years and have found various applications in high throughput particle sorting and separation. For separation applications, elasto-inertial microfluidics has thus far been applied at substantial lower flow rates as compared to inertial microfluidics. In this work, we explore viscoelastic particle focusing and separation in spiral channels at two orders of magnitude higher Reynolds numbers than previously reported. We show that the balance between dominant inertial lift force, dean drag force and elastic force enables stable 3D particle focusing at dynamically high Reynolds numbers. Using a two-turn spiral, we show that particles, initially pinched towards the inner wall using an elasticity enhancer, PEO (polyethylene oxide), as sheath migrate towards the outer wall strictly based on size and can be effectively separated with high precision. As a proof of principle for high resolution particle separation, 15 µm particles were effectively separated from 10 µm particles. A separation efficiency of 98% for the 10 µm and 97% for the 15 µm particles was achieved. Furthermore, we demonstrate sheath-less, high throughput, separation using a novel integrated two-spiral device and achieved a separation efficiency of 89% for the 10 µm and 99% for the 15 µm particles at a sample flow rate of 1 mL/min—a throughput previously only reported for inertial microfluidics. We anticipate the ability to precisely control particles in 3D at extremely high flow rates will open up several applications, including the development of ultra-high throughput microflow cytometers and high-resolution separation of rare cells for point of care diagnostics.

scholarly journals High Throughput Viscoelastic Particle Focusing and Separation in Spiral Microchannels

2021 ◽  
Author(s):  
Tharagan Kumar ◽  
Harisha Ramachandraiah ◽  
Sharath Narayana Iyengar ◽  
Indradumna Banerjee ◽  
Gustaf Mårtensson ◽  
...  
Keyword(s):  
High Resolution ◽  
High Throughput ◽  
Separation Efficiency ◽  
Point Of Care ◽  
Outer Wall ◽  
Reynolds Numbers ◽  
Inertial Microfluidics ◽  
Flow Rates ◽  
Particle Focusing ◽  
Sample Flow Rate

Abstract Passive particle manipulation using inertial and elasto-inertial microfluidics have received substantial interest in recent years and have found various applications in high throughput particle sorting and separation. For separation applications, elasto-inertial microfluidics has thus far been applied at substantial lower flow rates as compared to inertial microfluidics. In this work, we explore viscoelastic particle focusing and separation in spiral channels at two orders of magnitude higher Reynolds numbers than previously reported. We show that the balance between dominant inertial lift force, dean drag force and elastic force enables stable 3D particle focusing at dynamically high Reynolds numbers. Using a two-turn spiral, we show that particles, initially pinched towards the inner wall using an elasticity enhancer, PEO (polyethylene oxide), as sheath migrate towards the outer wall strictly based on size and can be effectively separated with high precision. As a proof of principle for high resolution particle separation, 15 µm particles were effectively separated from 10 µm particles. A separation efficiency of 98% for the 10 µm and 97% for the 15µm particles was achieved. Furthermore, we demonstrate sheath-less, high throughput, separation using a novel integrated two-spiral device and achieved a separation efficiency of 89% for the 10 µm and 99% for the 15µm particles at a sample flow rate of 1 mL/ml – a throughput previously only reported for inertial microfluidics. We anticipate the ability to precisely control particles in 3D at extremely high flow rates will open up several applications, including the development of ultra-high throughput microflow cytometers and high-resolution separation of rare cells for point of care diagnostics.

Experimental Study on Two Different Gas-Liquid Separators Under Different Flow Patterns

2020 ◽  
Author(s):  
Xiaobo Zeng ◽  
Changqi Yan ◽  
Guangming Fan ◽  
Jie Cheng ◽  
Junxiu Xu ◽  
...  
Keyword(s):  
Void Fraction ◽  
Slug Flow ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Experimental System ◽  
Flow Patterns ◽  
Separation Performance ◽  
Wide Range ◽  
Churn Flow ◽  
Gas Void Fraction

Abstract Gas-liquid separation is widely used in many fields, such as nuclear energy and petroleum resources. And the gas-liquid mixture separated gradually shows the characteristic of wide range of gas void fraction and variable flow patterns. However, the current separators only suit for narrow range of gas void fraction or single flow patterns. In this research, two different new type separators using centrifugal technology were designed and an experimental system was constructed to test the two separators using dry air and water under different flow patterns, including bubble, slug and churn flow. One was called inline separator consisting of three swirls and another was called double-layer cylinder separator composed of a central tube, a swirl and an outer tube. The results show that the separation performance of the inline separator was sensitive to flow patterns and the two-layer cylinder separator keeps high efficiency in different flow patterns. In bubble flow and slug flow patterns, the two separators kept high efficiency, while the oscillation of the gas core in the inline separator aggravated under slug flow condition. When increasing the gas void fraction, the turbulence of the churn flow led to the diameter of the gas core change drastically and reduce separation efficiency significantly.

scholarly journals High-Throughput, Label-Free Isolation of White Blood Cells from Whole Blood Using Parallel Spiral Microchannels with U-Shaped Cross-Section

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 406
Author(s):  
Amirhossein Mehran ◽  
Peyman Rostami ◽  
Mohammad Said Saidi ◽  
Bahar Firoozabadi ◽  
Navid Kashaninejad
Keyword(s):  
Cross Section ◽  
High Throughput ◽  
Whole Blood ◽  
Blood Cells ◽  
High Efficiency ◽  
Rectangular Cross Section ◽  
White Blood Cells ◽  
Label Free ◽  
Entire Cross Section ◽  
Shaped Cross Section

Rapid isolation of white blood cells (WBCs) from whole blood is an essential part of any WBC examination platform. However, most conventional cell separation techniques are labor-intensive and low throughput, require large volumes of samples, need extensive cell manipulation, and have low purity. To address these challenges, we report the design and fabrication of a passive, label-free microfluidic device with a unique U-shaped cross-section to separate WBCs from whole blood using hydrodynamic forces that exist in a microchannel with curvilinear geometry. It is shown that the spiral microchannel with a U-shaped cross-section concentrates larger blood cells (e.g., WBCs) in the inner cross-section of the microchannel by moving smaller blood cells (e.g., RBCs and platelets) to the outer microchannel section and preventing them from returning to the inner microchannel section. Therefore, it overcomes the major limitation of a rectangular cross-section where secondary Dean vortices constantly enforce particles throughout the entire cross-section and decrease its isolation efficiency. Under optimal settings, we managed to isolate more than 95% of WBCs from whole blood under high-throughput (6 mL/min), high-purity (88%), and high-capacity (360 mL of sample in 1 h) conditions. High efficiency, fast processing time, and non-invasive WBC isolation from large blood samples without centrifugation, RBC lysis, cell biomarkers, and chemical pre-treatments make this method an ideal choice for downstream cell study platforms.

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

Recent Advances in Heterostructured Photocatalysts for Degradation of Organic Pollutants.

2020 ◽  
Vol 17 ◽  
Author(s):  
Chen-Jing Sun ◽  
Li-Ping Zhao ◽  
Rui Wang
Keyword(s):  
Organic Pollutants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Organic Pollution ◽  
Utilization Rate ◽  
Type I ◽  
Human Beings ◽  
Global Challenge ◽  
Global Environmental ◽  
High Efficient

: With the development of industrialization, the global environmental pollution and energy crisis are becoming increasingly serious. Organic pollutants pose a serious health threat to human beings and other organisms. The removal of organic pollutants in environment has become a global challenge. The photocatalytic technology has been widely used in the degradation of organic pollutants with its characteristics of simple process, high efficiency, thorough degradation and no secondary pollution. However, the single photocatalyst represented by TiO2 has disadvantages of low light utilization rate and high recombination rate of photocarriers. Building heterojunction is considered one of the most effective methods to enhance the photocatalytic performance of single photocatalyst, which can improve the separation efficiency of photocarriers and utilization of visible light. The classical heterojunction can be divided into four different cases: type I, typeⅡ, p–n heterojunctions and Z-scheme junction. In this paper, the recent progress in the treatment of organic pollution by heterostructure photocatalysts is summarized and the mechanism of heterostructure photocatalysts for the treatment of organic pollutants is reviewed. It is expected that this paper can deepen the understanding of heterostructure photocatalysts and provide guidance for high efficient photocatalytic degradation of organic pollutants in the future.

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