Advantages Of Throughput Research Articles

A Simple, Low‐Blank Batch Purification Method for High‐Precision Boron Isotope Analysis

AbstractBoron (B) isotopes are widely used in the Earth sciences to trace processes ranging from slab recycling in the mantle to changes in ocean pH and atmospheric CO2. Boron isotope analysis is increasingly achieved by multi‐collector inductively coupled plasma mass spectrometry, which requires separation of B from the sample matrix. Traditional column chromatography methods for this separation have a well‐established track record but are time consuming and prone to contamination from airborne blank. Here, we present an extensive array of tests that establish a novel method for B purification using a batch method. We discuss the key controls and limitations on sample loading, matrix removal and B elution including sample volume, ionic strength, buffer to acid ratio and elution volume, all of which may also help optimize column‐based methods. We find consistent, low procedural blanks of 10 ± 16 pg and excellent reproducibility: 10 ng NIST RM 8301 foram [8301f] yields 14.58 ± 0.11‰ 2SD n = 15; 2.5 ng 8301f yields 14.60 ± 0.19‰ 2SD, n = 31; and overall long term 2SD on n = 218 samples pooling different sample sizes yields 14.62 ± 0.21‰ 2SD. This method also offers significant advantages in throughput, allowing the processing of 24 samples in ∼5 hr. This boron batch method thus provides a fast, reproducible, low‐blank method for purification of boron for high precision isotopic analyses.

Multimode chromatography‐based techniques for high purity isolation of extracellular vesicles from human blood plasma

AbstractExtracellular vesicles (EVs) play a pivotal role in various biological pathways, such as immune responses and the progression of diseases, including cancer. However, it is challenging to isolate EVs at high purity from blood plasma and other biofluids due to their low abundance compared to more predominant biomolecular species such as lipoprotein particles and free protein complexes. Ultracentrifugation‐based EV isolation, the current gold standard technique, cannot overcome this challenge due to the similar biophysical characteristics of such species. We developed several novel approaches to enrich EVs from plasma while depleting contaminating molecular species using multimode chromatography‐based strategies. On average, we identified 716 ± 68 and 1054 ± 35 protein groups in EV isolates from 100 µL of plasma using multimode chromatography‐ and ultracentrifugation‐based techniques, respectively. The developed methods resulted in similar EV isolates purity, providing significant advantages in simplicity, throughput, scalability, and applicability for various downstream analytical and potential clinical applications.

Portable, and ultrasensitive HR-HPV tests based on nucleic acid biosensors.

Cervical cancer is the third most common cancer threatening women's health globally, and high-risk human papillomavirus (HR-HPV) infection is the main cause of cervical cancer worldwide. Given the recurrent nature of HR-HPV infection, accurate screening is essential for its control. Since the commonly used polymerase chain reaction (PCR) technique is limited by professional equipment and personnel, convenient and ultrasensitive detection methods for HR-HPV are still highly needed. As new molecular detection methods, nucleic acid amplification-based biosensors have the advantages of high sensitivity, rapid operation, and portability, which are helpful for point-of-care testing in rural and remote areas. This review summarized nucleic acid biosensors for HR-HPV screening based on a variety of nucleic acid amplification strategies involved in improved PCR, loop-mediated isothermal amplification, recombinase polymerase amplification, hybridization chain reaction, catalyzed hairpin assembly, and CRISPR/Cas systems. In combination with microfluidic technology, lateral flow assays, electrochemical analysis and other sensing technologies, HR-HPV nucleic acid biosensors have the advantages of high throughput, short response time, high sensitivity and easy operation in the field. Although there are still shortcomings, such as high cost and poor reproducibility, this approach will be suitable for on-site screening of HR-HPV infection or cervical cancer and for auxiliary clinical diagnosis in complex environments and poor areas in the future.

Dual-Interference Channels Static Fourier Transform Imaging Spectrometer Based on Stepped Micro-Mirror: Data Processing and Experiment Research

The use of a dual-interference channels static Fourier transform imaging spectrometer based on stepped micro-mirror (D-SIFTS) for environmental gas monitoring has the advantages of high throughput, a compact structure, and a stable performance. It also has the characteristics of both a broad spectral range and high spectral resolution. However, its unique structural features also bring many problems for subsequent data processing, mainly including the complex distribution of the interference data, the low signal-to-noise ratio (SNR) of infrared scene images, and a unique inversion process of material information. To this end, this paper proposes a method of image and spectra information processing and gas concentration inversion. A multiscale enhancement algorithm for infrared images incorporating wavelet denoising is used to obtain high-quality remote sensing scene images, and spectral reconstruction optimization algorithms, such as interference intensity sequence resampling, are used to obtain accurate spectral information; the quantitative calibration model of the detected gas concentration is established to achieve high-precision inversion of gas concentration, and its distribution is visualized in combination with the scene image. Finally, the effectiveness and accuracy of the data processing algorithm are verified through the use of several experiments, which provide essential theoretical guidance and technical support for the practical applications of D-SIFTS.

Advancements in Reference Gene Selection for Fruit Trees: A Comprehensive Review.

Real-time quantitative polymerase chain reaction (qRT-PCR) has been widely used in gene expression analyses due to its advantages of sensitivity, accuracy and high throughput. The stability of internal reference genes has progressively emerged as a major factor affecting the precision of qRT-PCR results. However, the stability of the expression of the reference genes needs to be determined further in different cells or organs, physiological and experimental conditions. Methods for evaluating these candidate internal reference genes have also evolved from simple single software evaluation to more reliable and accurate internal reference gene evaluation by combining different software tools in a comprehensive analysis. This study intends to provide a definitive reference for upcoming research that will be conducted on fruit trees. The primary focus of this review is to summarize the research progress in recent years regarding the selection and stability analysis of candidate reference genes for different fruit trees.

Architectural Synthesis of Continuous-Flow Microfluidic Biochips with Connection Pair Optimization

Continuous-flow microfluidic biochips are a type of biochip technology based on microfluidic channels that enable various biological experiments and analyses to be performed on a tiny chip. They have the advantages of a high throughput, high sensitivity, high precision, low cost, and quick response. In the architectural synthesis of continuous-flow microfluidic biochips (CFMBs), prior work has not considered reducing component interconnection requirements, which led to an increase in the number of connection pairs. In this paper, we propose an architectural synthesis flow for continuous-flow microfluidic biochips with connection pair optimization, which includes high-level synthesis, placement, and routing. In the high-level synthesis stage, our method reduces the need for component interconnections, which reduces the number of connection pairs. Our method performs fine-grained binding, ultimately obtaining high-quality binding and scheduling results for flow paths. Based on the high-quality binding results, we propose a port placement strategy based on port correlation and subsequently use a quadratic placer to place the components. During the routing stage, we employ a conflict-aware routing algorithm to generate flow channels to reduce conflicts between liquid transportation tasks. Experimental results on multiple benchmarks demonstrate the effectiveness of our method. Compared with the existing work, the proposed algorithm obtains average reductions of 35.34% in connection pairs, 24.30% in flow channel intersections, 21.71% in total flow channel length, and 18.39% in the execution time of bioassays.

A compact and high-performance setup of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D).

Capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) has the advantages of high throughput (simultaneous detection of multiple ions), high separation efficiency (higher than 105 theoretical plates) and rapid analysis capability (less than 5 min for common inorganic ions). A compact CE-C4D system is ideal for water quality control and on-site analysis. It is suitable not only for common cations (e.g. Na+, K+, Li+, NH4+, Ca2+, etc.) and anions (e.g. Cl-, SO42-, BrO3-, etc.) but also for some ions (e.g. lanthanide ions, Pb2+, Cd2+, etc.) that require complex derivatization procedures to be detected by ion chromatography (IC). However, an obvious limitation of the CE-C4D method is that its sensitivity (e.g. 0.3-1 μM for common inorganic ions) is often insufficient for trace analysis (e.g. 1 ppb or 20 nM level for common inorganic ions) without preconcentration. For this technology to become a powerful and routine analytical technique, the system should be made compact while maintaining trace analysis sensitivity. In this study, we developed an all-in-one version of the CE-C4D instrument with custom-made modular components to make it a convenient, compact and high-performance system. The system was designed using direct digital synthesis (DDS) technology to generate programmable sinusoidal waveforms with any frequency for excitation, a kilovolt high-voltage power supply for capillary electrophoresis separation, and an "effective" differential C4D cell with a low-noise circuitry for high-sensitivity detection. We characterized the system with different concentrations of Cs+, and even a low concentration of 20 nM was detectable without preconcentration. Moreover, the optimized CE-C4D setup was applied to analyse mixed ions at a trace concentration of 200 nM with excellent signal-to-noise ratios. In typical applications, the limits of detection based on the 3σ criterion (without baseline filtering) were 9, 10, 24, 5, and 12 nM for K+, Cs+, Li+, Ca2+, and Mg2+, respectively, and about 7, 6, 6 and 6 nM for Br-, ClO4-, BrO3- and SO42-, respectively. Finally, the setup was also applied for the analysis of all 14 lanthanide ions and rare-earth minerals, and it showed an improvement in sensitivity by more than 25 times.

Microfluidic impedance cytometry with flat-end cylindrical electrodes for accurate and fast analysis of marine microalgae.

Marine microalgae play an increasingly significant role in addressing the issues of environmental monitoring and disease treatment, making the analysis of marine microalgae at the single-cell level an essential technique. For this, we put forward accurate and fast microfluidic impedance cytometry to analyze microalgal cells by assembling two cylindrical electrodes and microchannels to form a three-dimensional detection zone. Firstly, we established a mathematical model of microalgal cell detection based on Maxwell's mixture theory and numerically investigated the effects of the electrode gap, microalgal positions, and ion concentrations of the solution on detection to optimize detection conditions. Secondly, 80 μm stainless steel wires were used to construct flat-ended cylindrical electrodes and were then inserted into two collinear channels fabricated using standard photolithography techniques to form a spatially uniform electric field to promote the detection throughput and sensitivity. Thirdly, based on the validation of this method, we measured the impedance of living Euglena and Haematococcus pluvialis to study parametric influences, including ion concentration, cell density and electrode gap. The throughput of this method was also investigated, which reached 1800 cells per s in the detection of Haematococcus pluvialis. Fourthly, we analyzed live and dead Euglena to prove the ability of this method to detect the physiological status of cells and obtained impedances of 124.3 Ω and 31.0 Ω with proportions of 15.9% and 84.1%, respectively. Finally, this method was engineered for the analysis of marine microalgae, measuring living Euglena with an impedance of 159.61 Ω accounting for 3.9%, dead Euglena with an impedance of 36.43 Ω accounting for 10.1% and Oocystis sp. with an impedance of 55.00 Ω accounting for about 81.0%. This method could provide a reliable tool to analyze marine microalgae for monitoring the marine environment and treatment of diseases owing to its outstanding advantages of low cost, high throughput and high corrosion resistance.

Advances in microfluidic-based DNA methylation analysis

DNA methylation has been extensively investigated in recent years, not least because of its known relationship with various diseases. Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research. Microfluidic chips are excellent carriers for molecular analysis, and their use can provide improvements from multiple aspects. On-chip molecular analysis has received extensive attention owing to its advantages of portability, high throughput, low cost, and high efficiency. In recent years, the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods. In this review, we first focus on DNA methylation and its applications. Then, we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years. Finally, we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis. This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.

Effective task scheduling based on interactive autodidactic school algorithm for cloud computing

The topic of load balanced task scheduling has emerged as a prominent and intricate area of study within the realm of Cloud computing. Swarm intelligence-based meta-heuristic algorithms are commonly considered more suitable for the purposes of Cloud scheduling and load balancing. These algorithms employ a combination of local and global search strategies in order to ascertain the ideal location. To achieve an optimal mapping strategy for task allocation to resources, it is imperative to find a suitable equilibrium between local and global search techniques, since this approach has demonstrated significant efficacy. This research introduces a new approach to task scheduling using the Autodidactic Interactive School Optimization Algorithm (IASOA). The objective of this method is to decrease the time required for job execution while also enhancing throughput. The assessment of the suggested methodology has been executed, and a comparative analysis has been performed with five established algorithms in relation to makespan and throughput. The tests were subsequently extended to encompass a comparative analysis of the suggested methodology alongside four other established meta-heuristic scheduling methodologies. The study of the simulated experimentation reveals that the proposed approach yielded noteworthy advantages in makespan and throughput, with improvements of up to 10% and 60% respectively.

Separation of acetonitrile/water with the combination of superwetting membrane and salt-induced phase separation

Efficient recovery of acetonitrile from its aqueous solution is quite important for both cost reduction and avoiding environmental pollution. The current main strategies including pervaporation, absorptive separation, and extractive distillation are limited by their low separation-flux, low separation-capacity, or high energy-consumption. Herein, we combine the design of superwetting membrane and salt-induced phase separation to propose a new approach for purification of acetonitrile from its aqueous solution, which possesses the advantages of high throughput, continuity, and energy conservation.

Microfluidic Platforms for Real-Time In Situ Monitoring of Biomarkers for Cellular Processes.

Cellular processes are mechanisms carried out at the cellular level that are aimed at guaranteeing the stability of the organism they comprise. The investigation of cellular processes is key to understanding cell fate, understanding pathogenic mechanisms, and developing new therapeutic technologies. Microfluidic platforms are thought to be the most powerful tools among all methodologies for investigating cellular processes because they can integrate almost all types of the existing intracellular and extracellular biomarker-sensing methods and observation approaches for cell behavior, combined with precisely controlled cell culture, manipulation, stimulation, and analysis. Most importantly, microfluidic platforms can realize real-time in situ detection of secreted proteins, exosomes, and other biomarkers produced during cell physiological processes, thereby providing the possibility to draw the whole picture for a cellular process. Owing to their advantages of high throughput, low sample consumption, and precise cell control, microfluidic platforms with real-time in situ monitoring characteristics are widely being used in cell analysis, disease diagnosis, pharmaceutical research, and biological production. This review focuses on the basic concepts, recent progress, and application prospects of microfluidic platforms for real-time in situ monitoring of biomarkers in cellular processes.

Surface plasmon resonance sensor based on polarization parameter SPR imaging

Using polarization surface plasmon resonance (SPR) imaging as a sensor has the advantage of large throughput in detection, but its sensitivity has always been inferior to other SPR sensors. The high contrast of the two polarization parameters’ images related to scattering determines the high sensitivity of this new polarization SPR imaging sensor. It provides a new direction for solving the issue of low sensitivity in polarization SPR imaging. The sensor system was optimized by numerical simulation, whilst the baseline noise and sensitivity of the system were obtained by saline solution and virus detection. When the reflective index of the NaCl solution is within the range of 1.3331 to 1.36, the average sensitivity can reach 9300 RIU-1, and the maximum sensitivity can reach 13000 RIU-1. Using this new polarization SPR imaging sensor, the H1N1 virus was differentiated, showing its promising application potential within the field of biomedicine.

An improved PBFT consensus mechanism with trust value evaluation application in the agricultural product trusted traceability system

Blockchain has the advantages of tamper proof, high reliability and traceability, so it can better support the agricultural product traceability system. However, the agricultural product supply chain has the characteristics of long chain and decentralized production, which makes the application of the combination of blockchain technology and agricultural product traceability have many nodes, large system overhead and other problems. In order to solve the above problems, this paper proposes a Practical Byzantine Fault Tolerance (PBFT) consensus mechanism based on trust value evaluation, and uses this optimization algorithm to propose an architecture model to meet the demand for trusted traceability of agricultural product supply chain, so as to realize the distributed storage and security protection of supply chain data. In order to ensure the effective operation of the blockchain system, this paper studies the consensus mechanism in the blockchain network, designs a trust value evaluation model to calculate the trust value of nodes, and selects trusted nodes to join the consensus group based on the trust value, which ensures the credibility of the consensus nodes. At the same time, the consistency protocol is optimized to reduce the communication overhead in the consensus process. The experimental results show that the consensus mechanism improved in this paper has certain advantages in communication overhead, transaction delay and throughput. Compared with the existing storage model, the model described in this paper has higher security and throughput efficiency, effectively ensures the reliable traceability of data, and can be better applied to the traceability scenario of agricultural product supply chain.

Comparative Evaluation of Host-Based Translator Mechanisms for IPv4-IPv6 Communication Performance Analysis With Different Routing Protocols

The impending exhaustion of internet protocol (IP) version four (IPv4) addresses necessitates a transition to the more expansive IP version six (IPv6) protocol. However, this shift faces challenges due to the widespread legacy of IPv4 infrastructure and resistance among organizations to overhaul networks. Host-based translators offer a critical bridging solution by enabling IPv6-only devices to communicate with IPv4-only devices through software-level protocol translation. This paper comprehensively evaluates four pivotal host-based translator mechanisms—bump-in-the-stack (BIS), bump-in-the-application programming interface (API) (BIA), BIA version 2 (BIAv2), and bump-in-the-host (BIH). Using simulated networks with diverse configurations of IPv4/IPv6 applications, hosts, and routing protocols, the authors assessed performance through metrics including packet loss, convergence time, traffic throughput, and overhead. The results reveal variability in effectiveness across both translators and scenarios. BIAv2 demonstrated advantages in throughput and overhead due to stateless mapping. The research underscores the importance of selecting the optimal translation approach for specific network environments and goals. It guides smoother IPv6 adoption by demonstrating how host-based translators can facilitate coexistence during transition. Further exploration of performance tradeoffs can continue guiding effective deployment strategies.

Vertical structure selection and evolution in shipping supply chains under bilateral bargaining

Fierce port competition and asymmetric bargaining power may lead to multiple vertical cooperation patterns between ports and shipping companies. The value analysis of vertical cooperation and structure preference are crucial to the evolution regularity of shipping supply chains. In a two-tier shipping supply chain consisting of competitive ports and shipping companies, we propose three typical vertical structures of shipping supply chain: port-shipping alliance, vertical integration, and cross-berthing. We show that the port-shipping alliance has the advantages of low freight rate and high throughput, but may reduce the overall performance of the shipping system. Although vertical integration helps to weaken service competition and enhance the monopoly of ports, it increases the freight rate and reduces the throughput. Cross-berthing increases the pricing power and throughput of ports, but it will bring fierce internal competition. With the increasing bargaining power of shipping company and the degree of port competition, the vertical structure evolves from the port-shipping alliance and cross-berthing to the structure with only cross-berthing, and finally turns into vertical integration. From the perspective of the overall shipping system, each evolution stable state will achieve the Pareto-optimization.

A fluorescence sensing array based on photonic crystals and RAA for sensitive and high-throughput detection of Salmonella in foods

Salmonella can cause serious foodborne diseases, which is a major concern for global public health. The sensitive and fast analysis of Salmonella is of importance for food safety. Herein, we developed a fluorescence sensing array based on photonic crystals (PCs) and recombinase-aided amplification (RAA) for high-throughput and high-sensitive analysis of Salmonella in foods. In this assay, RAA was employed for powerful amplification of the target DNA of Salmonella, and the generated dsDNA amplicon was embedded with nucleic acid dye SYBR Green I (SGI), emitting fluorescence. Furthermore, the fluorescence signal was physically enhanced by PCs array; meanwhile, the high-throughput and sensitive detection was realized by microplate reader. Because of the isothermal reaction and lyophilized regent of RAA, the proposed array possessed gentle operation and stable amplification performance. Besides, a small volume of loading samples with 2 μL was required on the PCs array for powerful fluorescence enhancement. Due to the synergistic signal amplification effect of RAA and photonic crystals, a low limit of detection (LOD) of 10 CFU/mL was achieved. Besides, the proposed array exhibited excellent performance with 100% accuracy in 20 spiked food samples. Therefore, the proposed method with the advantages of sensitivity and high throughput showed great application potential.

Battery Materials: In-Situ Analysis with the Scanning Electron Microscope

The concept of decarbonisation has been gradually gaining ground. As a result, emphasis has been given to green energy technology in an attempt to offset the need for fossil fuels. The alternative to fossil fuels could be batteries. Not only can batteries be used for stationary energy storage but also for powering electric vehicles. However, more is increasingly required from batteries: they have to store more energy, perform reliably and function for longer, often under extreme conditions depending on the latitude. Among the different battery technologies that have been developed over the years, lithium ion batteries stand out. The main reason is their superior energy and power density, which can support demanding applications such as electromobility. The drive to make batteries more efficient and able to hold more energy, and eventually deliver more power requires in-depth analysis of materials; in order to understand what promotes or undermines materials performance, what leads to failure, and ultimately, the knowledge to design materials for the next generation of batteries.The scanning electron microscope is a powerful tool supporting in situ analysis of materials. In the short-term, as far as cathode precursor powders are concerned, costs are reduced by early detection of impurities and contamination. In the long-term, the battery quality and performance are safeguarded as failure caused by the presence of contaminants is minimised (contamination particles cause short-circuits by penetrating through the battery components). Scanning electron microscope(SEM)-based quality assurance/quality control of battery powders is routinely done with energy dispersive spectroscopy (EDS) and comes with the advantage of high throughput and minimum instrument down time.Battery materials analysis often focuses on formulation testing. That can be either at the industrial level (enquiring if the result is the intended) or R&D level, that is, experimenting with different recipes to single out the optimal one(s). One of the aspects that can be checked using SEM-based analytical techniques is the composition and distribution of coatings and dopants on the powder particle surface. The addition of coatings (Figure 1A) and dopants (Figure 1B) is crucial to ensuring battery performance. They act as performance enhancers (coatings) and dendrite formation suppressants (dopants). These can be detected and mapped in high resolution with SEM-EDS and they can be analysed more accurately with SEM-WDS. At a later stage, the same techniques can be applied to analyse black mass, the material coming from shredded, spent batteries.Given that the atomic numbers (Z) of the elements comprising the battery powders are often close, there is a limit to the information that an electron image can provide due to the closeness of the grey levels. However, there is need to characterise the internal structure of precursor cathode powders as well as other properties such as shape, size, grain boundaries and texture. SEM-EBSD can bypass this issue and can provide information about the particle internal structure by utilising backscattered electrons. The internal structure information of the particles can be used to study cracking development and propagation. A useful tool for battery components post-mortem analysis. The incorporation the Raman-in-SEM, RISE system provides an additional dimension to battery analysis, meaning we can access a wealth of molecular information. Raman spectroscopy can be employed to aid with the analysis of lithium-containing cathode materials in addition to investigating graphitic carbon anode materials.The primary benefit of the SEM-based techniques briefly discussed here is that they can all be applied in the same SEM chamber, in situ, allowing for data to be obtained under the same conditions as part of the same experiment/workflow, promoting, thus, efficiency and throughput – even more so for beam and/or air sensitive samples, saving time required for sample (re)preparation. Another practical benefit is straightforward data correlation which is facilitated when the exact same sample locations have been analysed. Figure 1

Method development and validation of unbound saccharide content (serogroup A, C, Y, W, X) in novel pentavalent meningococcal polysaccharide conjugate vaccine with two different carrier proteins

Exclusive DOC-HCl formulations were developed for free polysaccharide content estimation in Meningococcal serogroup A, C, Y, W and X from pentavalent meningococcal vaccine (A, C, Y, W, X). The DOC precipitation method reported herein stands as an alternative to the ultra-filtration method for free polysaccharide estimation. DOC content was optimized for all the serogroups at a single concentration, where as effective acid concentration was altered as per serogroup. Briefly, two DOC-HCl formulations were developed for intended purpose, one for TT conjugated serogroups Men A & Men X where as other for CRM conjugated serogroups Men C, Men Y and Men W with effective HCl concentration of 23 mM and 193 mM for precipitation of Protein-DOC complex respectively. Furthermore, an exclusive buffer/DOC-HCl formulation for estimation of Men X free polysaccharide in fill finished product was developed. Accuracy of the method was proven at 12.5 %, 25 %, 50 % and 100 % of test specification where recoveries were found in the range of 70–130 %. In case of repeatability, intra assay variation ranged from 2 % to 7 % whereas inter assay variation was noted to be 2–14 %. Specificity studied revealed no interference of assay components such as sample excipients, DOC, acids. Critical quality and stability-indicating characteristics were measured. Monovalent polysaccharide standards of Men A, C, Y, W and X were developed and assigned the unitage concentration 1.01, 1.10, 1.09, 1.08 and 1.00 mg/mL respectively. Linearity curve was optimized from 0.17 to 27 µg/mL for Men A and C whereas from 0.33 to 27 µg/mL for Men Y and W considering free polysaccharide content estimation. The study suggests that DOC-HCl method meets all the criteria for free polysaccharide estimation in multivalent vaccines with additional advantages of high throughput and sized independent separation hence can be used for quality control testing.

An impedance flow cytometry with integrated dual microneedle for electrical properties characterization of single cell

Electrical characteristics of living cells have been proven to reveal important details about their internal structure, charge distribution and composition changes in the cell membrane, as well as the extracellular context. An impedance flow cytometry is a common approach to determine the electrical properties of a cell, having the advantage of label-free and high throughput. However, the current techniques are complex and costly for the fabrication process. For that reason, we introduce an integrated dual microneedle-microchannel for single-cell detection and electrical properties extraction. The dual microneedles utilized a commercially available tungsten needle coated with parylene. When a single cell flows through the parallel-facing electrode configuration of the dual microneedle, the electrical impedance at multiple frequencies is measured. The impedance measurement demonstrated the differential of normal red blood cells (RBCs) with three different sizes of microbeads at low and high frequencies, 100 kHz and 2 MHz, respectively. An electrical equivalent circuit model (ECM) was used to determine the unique membrane capacitance of individual cells. The proposed technique demonstrated that the specific membrane capacitance of an RBC is 9.42 mF/m−2, with the regression coefficients, at 0.9895. As a result, this device may potentially be used in developing countries for low-cost single-cell screening and detection.