Gel Separation Research Articles

Influence of reduced centrifugation time on clinical chemistry analytes and literature review

Abstract Objectives Centrifugation is a time-consuming step which increases the turnaround time (TAT) in laboratories. A few studies have addressed the effect of altering centrifugation settings on analytical quality for clinical chemistry analytes, and most of these studies have used collection tubes with gel separators. However, gel separator tubes may be unsuitable for some laboratories because they are slightly more expensive than tubes without gel separators and are not appropriate for some special tests. The aim of this study was to investigate the effect of centrifugation conditions on clinical chemistry analytes. Methods We compared centrifugation times of 7 min at 2,200×g and 5 min at 2,750×g with the manufacturer’s protocol of 10 min at 1,300×g as the reference condition. Twenty general chemistry analytes were studied in lithium heparin plasma tubes without gel separators. Results For all analytes except carbon dioxide (CO2), no significant differences in analyte results were observed when the centrifugation time was reduced. Deming regression and Bland–Altman plots demonstrated an acceptable clinical concordance within the limits of total allowable error for all analytes between the two rapid centrifugation conditions with the reference centrifugation condition. Conclusions Our results confirmed that alternate centrifugation conditions for either 7 min at 2,200×g or 5 min at 2,750×g of samples collected in lithium heparin tubes without gel are acceptable for clinical chemistry analytes. Our data support using centrifugation at higher speeds for shorter times to improve TAT without altering the quality of the analytical results.

Identification, flavor characteristics and molecular docking of umami taste peptides of Xuanwei ham

To better understand the palatable properties of Xuanwei ham, the aqueous extract was isolated, analyzed and combin with sensory evaluation. Of umami-tasting activity and umami-enhancing impact, four new peptides (MDAIKKMQ, RKYEEVAR, YVGDEAQSKRG, and VNVDEVGGEALGR) were extracted and identified by ultrafiltration, gel separation, reverse performance liquid chromatography, and nano-LC-MS / MS. Sensory evaluation results showed that all of them had umami activity and enhanced umami taste, among which VNVDEVGGEALGR had the best effect. These peptides' umami taste thresholds ranged from 0.25 to 0.8 mg/mL. The MSG solution's umami taste threshold ranged from 0.125 to 0.5 mg/mL. Molecular docking results showed that the four umami peptides could be embedded into the binding pocket of the T1R3 cavity of the umami taste receptor T1R1/T1R3, wherein the binding sites Asp219, Asp150, and Thr179 may play crucial roles, and Glu222, Asp108, Glu217 and Glu148 play auxiliary roles. Hydrogen bonding and hydrophobic interactions were the most prominent interaction forces. This study helps to clarify the flavor characteristics of Xuanwei ham and could improve new processing technology.

SDS-Page Analysis Of Cysticercus tenuicollis In Vitro And In Vivo In Basrah Province/ Southern Iraq

The larval stage Cysticercus tenuicollis was isolated from slaughtered sheep and goats at the Basrah slaughterhouse with 30 samples. In vitro 16 samples, 2 control, and 14 were treated with plant extracts and novel chemical compounds. In vivo 14 sample,1 control and 13 treated with plant extracts and novel chemical compounds.. SDS- page electrophoresis using the gel as separation gel of larval stage Cysticercus tenuicollis. Lanes (C) control, (A) Syzygium aromaticum, (B) Capparis spinosa, novel acylselenourea, i.e., 4-Nitro-N-((4-(N-(pyrimidin-2-yl) sulfamoyl) phenyl) carbamoselenoyl) Benz amide (1), 4-Methyl-N-((4-(N-(pyrimidin-2-yl) sulfamoyl) phenyl) carbamoselenoyl) Benz amide (2), 4-Nitro-N-((4-nitrophenyl) carbamo selenoyl) Benz amide (4), N-(2,6-dioxo-1,2,3,6-tetrahydropyrimidine-1-carbonoselenoyl)-4-nitrobenzamide (5) and novel acylthiourea 4-Methyl-N-((4-(N-(pyrimidin-2-yl) sulfamoyl phenyl) carbamothioyl) Benz amide (3). The rats were administered plant extracts and synthesis compounds orally via mouth for 15 days, Then the rats were dissected, the cysts were isolated, and their SDS page was measured.The results found in in vitro, all plant extracts, and synthesized compounds bands ranged from 67 to 17KD. In contrast, the protein bands of cysts varied from 67 to 17KD in vivo whereas Capparis spinosa and the synthetic chemical (5) showed no bands. This study recorded a clear effect on protein cotenants of C. tenuicollis which was treated with two plant extracts C. spinosa and S. aromaticum, and five novel chemical synthesized compounds in vitro and in vivo by SDS- PAGE as compared with untreated.

Combination of AAV-delivered tumor suppressor PTEN with anti-PD-1 loaded depot gel for enhanced antitumor immunity

Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene in cancer cells may be associated with immunosuppressive tumor microenvironment (TME) and poor response to immune checkpoint blockade (ICB) therapy. Therefore, efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy. Here, we screened an adeno-associated virus (AAV) capsid for efficient PTEN gene delivery into B16F10 tumor cells. We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death (ICD) and increasing immune cell infiltration. Moreover, we developed an anti-PD-1 loaded phospholipid-based phase separation gel (PPSG), which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo. In order to effectively inhibit the recurrence of melanoma, we further applied a triple therapy based on AAV6-PTEN, PPSG@anti-PD-1 and CpG, and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory, which completely rejected tumor recurrence. We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.

Synthesis of Porous MgF2 Coating by a Sol–Gel Method Accompanied by Phase Separation

Surfaces with translucent and wear-resistant effects have a wide range of applications, especially as protective layers. In this work, a simple and convenient method for the preparation of porous magnesium fluoride (MgF2) coatings was proposed. Nano-porous MgF2 powder was prepared with sol–gel and phase separation methods by optimizing the polymer amount and used for the preparation of thick layers onto PVC substrates. The automated surface area and porosity analyzer (BET) and scanning electron microscopy (SEM) confirmed that the layers containing 0.028‰ PEO presented a 3D structure with pore sizes in the range of 16 nm. The layer reached 93% transmittance in the visible region, a Vickers hardness value of 2889.1 kg/mm2, and a friction coefficient of 0.2 in the wear test.

Hydrogen-bonding polymer complexation: Coacervation interfered with gelation

Complexation between polymers of different species in a common solvent is a fundamental process in various applications such as functional polymeric membrane and drug delivery, yet the understanding of energetics, phase behaviors, and kinetics of polymer complexation is rather challenging partially due to the multi-component nature of the system. In this work, we investigate the hydrogen-bonding complexation of poly(acrylic acid) (PAA) and poly(vinylpyrrolidone) (PVPON) in different solvents, and identify a variety of phase states, including homogenous solution, solid precipitate, liquid–liquid separation, gelation, and kinetically trapped structures. Among different solvents, N-methyl-2-pyrrolidone (NMP) has a similar structure to the repeating unit of PVPON and the complexation in NMP almost has no heat, suggesting the process is driven by entropy. The PAA/PVPON-NMP system exhibits an upper critical solution temperature; specifically, as the temperature decreases, a homogeneous solution first becomes opalescent, then undergoes a liquid–liquid separation, and finally undergoes a liquid–gel separation. On the other hand, when the polymer concentration is above a threshold, a homogenous solution turns into a gel directly without involving liquid–liquid separation with decreasing temperature. Accordingly, we construct a temperature–concentration phase diagram that shows how the gelation interplays with coacervation. This work provides a broad vision on phase behaviors of polymer complexation.

Comparison of Serum Stability against Uric Acid and Glucose

The selection of tools, especially the use of vacutainer tubes, affects the results of the examination to determine the stability of serum from plain vacutainer with vacutainer separation gel on the quality of uric acid and glucose test results. This study used an experimental design. The study took blood samples of 3 ml each in SST vacutainer and plain vacutainer serum. The mean uric acid levels using plain vacutainer and SST vacutainer were 4.5875±0.59048 and 4.9250±0.56318, respectively. The mean glucose levels using plain vacutainer and SST vacutainer were 90.64±12.33 and 94.12±13.30, respectively. Uric acid and glucose levels using gel-separated vacutainer were higher than uric acid levels using plain vacutainer. There was a significant difference in uric acid levels between regular vacutainers and SST vacutainers, similar to glucose levels (p = 0.000, p = 0.000). Uric acid and glucose levels using SST vacutainer were higher than uric acid levels using plain vacutainer. The following types of vacutainer separator gel and plain vacutainer affect the quality of uric acid and glucose test results.

CONSUMPTION OF BROCCOLI SPROUTS INCREASED THE ACTIVITY OF GLUTATHIONE-DEPENDENT ANTIOXIDANT ENZYMES IN MURINE LIVER

Aim. The purpose of this work was to investigate effects of the consumption of broccoli sprouts on the activity of antioxidant defense enzymes in the liver of. GPx isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Methods. Frozen tissue was homozeniged in lysis buffer, centrifuged and resulted supernatants were used for analysis. Activities of enzymes were determined by using electrophoresis in polyacrylamide gel. After electrophoresis we conducted dyeing of separate gels for detection of superoxide dismutase (SOD), glutathione-S-transferase (GST) or glutathione peroxidase (GPx) isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Results. In the hepatic tissue of all four groups of mice, two isoforms of SOD (SOD1 and SOD2) were detected in gels. The intensity of the bands of both isoforms was not significantly different between groups. Three isoforms of GST (GST1, GST2, GST3) were detected in the liver samples. The activity of GST1 did not significantly differ between the experimental groups. Activities of GST2 and GST3 forms were significantly higher in the group “Broccoli” compared to Control and Cafeteria Diet groups. We identified three isoforms of glutathione peroxidase (GPx1, GPx2, GPx3) in liver samples. The activity of GPx isoform 1 was not significantly different between the experimental groups. The activity of GPx2 was significantly higher in the group of mice that consumed Broccoli and Cafeteria Diet + Broccoli compared to Control. GPx2 activity was significantly higher in the Broccoli group compared to the Cafeteria Diet group. Activity of GPx3 was significantly higher in the Broccoli group compared to the Control and Cafeteria Diet group. Conclusions. Cafeteria diet did not significantly affect the activity of SOD isoforms, but led to redistribution of in the activity of GST and GPx isoforms in murine liver. Feeding with broccoli spouts significantly increased the activity of 2 and 3 isoforms of GST and GPx in murine liver compared to values in control mice and mice fed with cafeteria diet. Combination of Broccoli + Cafereria diet had small activating effects on antioxidant enzyme acivity, compared with cafeteria diet.

Activation of Ca2+ transport in cardiac microsomes enriches functional sets of ER and SR proteins

The importance of sarcoplasmic reticulum (SR) Ca2+-handling in heart has led to detailed understanding of Ca2+-release and re-uptake protein complexes, while less is known about other endoplasmic reticulum (ER) functions in the heart. To more fully understand cardiac SR and ER functions, we analyzed cardiac microsomes based on their increased density through the actions of the SR Ca2+-ATPase (SERCA) and the ryanodine receptor that are highly active in cardiomyocytes. Crude cardiac microsomal vesicles loaded with Ca oxalate produced two higher density subfractions, MedSR and HighSR. Proteins from 20.0 μg of MV, MedSR, and HighSR protein were fractionated using SDS-PAGE, then trypsinized from 20 separate gel pieces, and analyzed by LC–MS/MS to determine protein content. From 62,000 individual peptide spectra obtained, we identified 1105 different proteins, of which 354 were enriched ≥ 2.0-fold in SR fractions compared to the crude membrane preparation. Previously studied SR proteins were all enriched, as were proteins associated with canonical ER functions. Contractile, mitochondrial, and sarcolemmal proteins were not enriched. Comparing the levels of SERCA-positive SR proteins in MedSR versus HighSR vesicles produced a range of SR subfraction enrichments signifying differing levels of Ca2+ leak co-localized in the same membrane patch. All known junctional SR proteins were more enriched in MedSR, while canonical ER proteins were more enriched in HighSR membrane. Proteins constituting other putative ER/SR subdomains also exhibited average Esub enrichment values (mean ± S.D.) that spanned the range of possible Esub values, suggesting that functional sets of proteins are localized to the same areas of the ER/SR membrane. We conclude that active Ca2+ loading of cardiac microsomes, reflecting the combined activities of Ca2+ uptake by SERCA, and Ca2+ leak by RyR, permits evaluation of multiple functional ER/SR subdomains. Sets of proteins from these subdomains exhibited similar enrichment patterns across membrane subfractions, reflecting the relative levels of SERCA and RyR present within individual patches of cardiac ER and SR.

Physicochemical property changes of Dendrobium officinale leaf polysaccharide LDOP-A and it promotes GLP-1 secretion in NCI-H716 cells by simulated saliva-gastrointestinal digestion.

A polysaccharide LDOP-A with a molecular weight of 9.9 kDa was isolated and purified from Dendrobium officinale leaves by membrane separation, cellulose column, and dextran gel column. The Smith degradable products, methylation products, and nuclear magnetic resonance analysis showed that LDOP-A may be composed of →4)-Glc-(1→, →3,6)-Man-(1→, and →6)-Glc-(1→sugar residues. In vitro, simulated digestion assays showed that LDOP-A could be partially digested in the stomach and small intestine, and produced a large amount of acetic acid and butyric acid during colonic fermentation. Further cell experiment results illustrated that LDOP-A-I (LDOP-A digested by gastrointestinal tract) could induce glucagon-like peptide-1 (GLP-1) secretion in NCI-H716 cells without showing any cytotoxicity.

The development of a solid lipid nanoparticle (SLN)-based lacticin 3147 hydrogel for the treatment of wound infections

Chronic wounds affect millions of people globally. This number is set to rise with the increasing incidence of antimicrobial-resistant bacterial infections, such as methicillin-resistant Staphylococcus aureus (MRSA), which impair the healing of chronic wounds. Lacticin 3147 is a two-peptide chain bacteriocin produced by Lactococcus lactis that is active against S. aureus including MRSA strains. Previously, poor physicochemical properties of the peptides were overcome by the encapsulation of lacticin 3147 into solid lipid nanoparticles. Here, a lacticin 3147 solid lipid nanoparticle gel is proposed as a topical treatment for S. aureus and MRSA wound infections. Initially, lacticin 3147’s antimicrobial activity against S. aureus was determined before encapsulation into solid lipid nanoparticles. An optimised gel formulation with the desired physicochemical properties for topical application was developed, and the lacticin-loaded solid lipid nanoparticles and free lacticin 3147 aqueous solution were incorporated into separate gels. The release of lacticin 3147 from both the solid lipid nanoparticle and free lacticin gels was measured where the solid lipid nanoparticle gel exhibited increased activity for a longer period (11 days) compared to the free lacticin gel (9 days). Both gels displayed potent activity ex vivo against S. aureus-infected pig skin with significant bacterial eradication (> 75%) after 1 h. Thus, a long-acting potent lacticin 3147 solid lipid nanoparticle gel with the required physicochemical properties for topical delivery of lacticin 3147 to the skin for the potential treatment of S. aureus-infected chronic wounds was developed.Graphical abstract

Chitosan derived porous carbon prepared by amino acid proton salt for high-performance quasi-state-solid supercapacitor

The electrode material and electrolyte are the major factors influencing the performance of supercapacitor, and they are the current research hotspots in this field. Herein, three chitosan (CS) based gel electrolytes were prepared by mixing CS with different acidity of amino acids (acidic, neutral and basic) proton salts. The CS/[Asp]NO3 gel film is prepared from aspartate nitrate proton salt ([Asp]NO3) formed by acid amino acid (aspartic acid, Asp) and CS exhibits superior mechanical property. This gel film can immerse in KOH or Na2SO4 solution directly and get alkaline and neutral gel electrolyte films. It possesses high ionic conductivity and excellent mechanical properties when used as gel electrolyte and separator in supercapacitor. Furthermore, the gel film can use as carbon precursor to prepare N-doped porous carbon (HN-HPCs). The as-prepared porous carbon exhibits large specific surface area (1599 m2 g−1), high micropore ratio (88%), hierarchical porous honeycomb structure and high N doping content (7.04 at%). The specific capacitance can reach up to 459 F g−1 in 6 M KOH. The assembled flexible quasi-solid-state supercapacitor using HN-HPCs and prepared gel electrolyte exhibits high energy densities of 28.3 Wh kg−1. It demonstrates an efficient strategy to prepare CS based gel electrolyte and simultaneously use the gel to prepare high N doping and hierarchical porous carbon. This work will provide guidelines for designing high-performance electrode material and electrolyte for flexible supercapacitor.

Finite-strain elasticity theory and liquid-liquid phase separation in compressible gels.

The theory of finite-strain elasticity is applied to the phenomenon of cavitation observed in polymer gels following liquid-liquid phase separation of the solvent, which opens a fascinating window on the role of finite-strain elasticity theory in soft materials in general. We show that compressibility effects strongly enhance cavitation in simple materials that obey neo-Hookean elasticity. On the other hand, cavitation phenomena in gels of flexible polymers in a binary solvent that phase separates are surprisingly similar to those of incompressible materials. We find that, as a function of the interfacial energy between the two solvent components, there is a sharp transition between cavitation and classical nucleation and growth. Next, biopolymer gels are characterized by strain hardening and even very low levels of strain hardening turn out to suppress cavitation in polymer gels that obey Flory-Huggins theory in the absence of strain hardening. Our results indicate that cavitation is, in essence, not possible for polymer networks that show strain hardening.

The Influence of Preanalytical Biospecimen Handling on the Measurement of B Vitamers, Amino Acids, and Other Metabolites in Blood.

Introduction: Sample handling can influence biomarker measurement and introduce variability when combining data from multiple studies or study sites. To inform the development of blood collection protocols within a multisite cohort study, we directly quantified concentrations of 54 biomarkers in blood samples subjected to different handling conditions. Materials and Methods: We obtained serum, lithium heparin plasma, and EDTA plasma from 20 adult volunteers. Tubes of chilled whole blood were either centrifuged and processed within 2 hours of collection (the "reference standard") or were stored with cool packs for 24 or 48 hours; centrifuged before and/or after this delay; or collected in tubes with/without gel separators. We used linear mixed models with random intercepts to estimate geometric mean concentrations and relative percent differences across the conditions. Results: Compared to the reference standard tubes, concentrations of many biomarkers changed after processing delays, but changes were often small. In serum, we observed large differences for B vitamers, glutamic acid (37% and 73% increases with 24- and 48-hour delays, respectively), glycine (12% and 23% increases), serine (16% and 27% increases), and acetoacetate (-19% and -26% decreases). Centrifugation timing and separator tube use did not affect concentrations of most biomarkers. Conclusion: Sample handling should be consistent across samples within an analysis. The length of processing delays should be recorded and accounted for when this is not feasible.

Effect of blood collection tubes containing separation gels on the measurement of drug concentrations in clinical toxicology

Effect of blood collection tubes containing separation gels on the measurement of drug concentrations in clinical toxicology

Active turbulence and spontaneous phase separation in inhomogeneous extensile active gels.

We report numerical results for the hydrodynamics of inhomogeneous lyotropic and extensile active nematic gels. By simulating the coupled Cahn-Hilliard, Navier-Stokes, and Beris-Edwards equation for the evolution of the composition, flow and orientational order of an active nematic, we ask whether composition variations are important to determine its emergent physics. As in active gels of uniform composition, we find that increasing either activity or nematic tendency (e.g., overall active matter concentration) triggers a transition between an isotropic passive phase and an active nematic one. We show that composition inhomogeneities are important in the latter phase, where we find three types of possible dynamical regimes. First, we observe regular patterns with defects and vortices: these exist close to the passive-active transition. Second, for larger activity, or deeper in the nematic phase, we find active turbulence, as in active gels of uniform composition, but with exceedingly large composition variation. In the third regime, which is uniquely associated with inhomogeneity and occurs for large nematic tendency and low activity, we observe spontaneous microphase separation into active and passive domains. The microphase separated regime is notable in view of the absence of an explicit demixing term in the underlying free energy which we use, and we provide a theoretical analysis based on the common tangent construction which explains its existence. We hope this regime can be probed experimentally in the future.

Protein-Protein Interaction Network Mapping by Affinity Purification Cross-Linking Mass Spectrometry (AP-XL-MS) based Proteomics.

Protein-protein interactions (PPIs) are the physical interactions formed among proteins. These interactions are primarily functional, i.e., they arise from specific biomolecular events, and each interaction interface serves a specific purpose. A significant number of methods have been developed for protein interactions in the field of proteomics in the last decade. Advanced mass spectrometry technology significantly contributed to the development of these methods. The rapid advancement of groundbreaking MS technology has greatly aided themapping ofprotein interaction from large-data sets comprehensively. This chapter describes the affinity purification (AP) mass spectrometry (MS)-based methods combined with chemical cross-linking (XL) of protein complexes. This chapter includes sample preparation methods involving cell culture, cell treatments with ligands, drugs, and cross-linkers, protein extractions, affinity purification, sodium dodecyl sulfate (SDS) polyacrylamide gel separation, in-solution or in-gel digestion, liquid-chromatography, and mass spectrometry analysis of samples (LC-MS/MS). Application of a cleavable cross-linker, dual cleavable cross-linking technology (DUCCT) in combination with the affinity purification (AP) method has also been described. Methods for data analysis using unmodified and cross-linked peptide analysis arediscussed.

Fractionation of Native Protein Complexes from Mammalian Cells to Determine the Differential Proteasome Activity and Abundance.

Eukaryotic cells have different types of proteasomes that differ in size. The smallest proteolytically active particle is the 20S proteasome, which degrades damaged and oxidized proteins; the most common larger particle is the 26S proteasome, which degrades ubiquitylated proteins. The 26S proteasome is formed by a 20S particle capped with one or two regulatory particles, named 19S. While proteasome particles function in the cytoplasm, endoplasmic reticulum, and nucleus, our understanding of their abundance and activity in different cellular compartments is still limited. We provide a three-step protocol that first involves detergent-based fractionation of the cytoplasmic and nuclear compartments, maintaining the integrity and activity of proteasome complexes. Second, the protocol employs native gel separation of large multiprotein complexes in the fractions and a fluorescence-based in-gel quantitation of the activity and different proteasome particles. Finally, the protocol involves protein in-gel denaturation and transfer to a PVDF membrane. Western blotting then detects and quantifies the different proteasome particles. Therefore, the protocol allows for sensitive measurements of activity and abundance of individual proteasome particles from different cellular compartments. It has been optimized for motor neurons induced from mouse embryonic stem cells but can be applied to a variety of mammalian cell lines. Key features • Protocol for fractionation of active nuclear and cytoplasmic proteasome complexes. • Native electrophoresis and fluorescence-based in-gel activity assay, which allows the visualization and quantification of active complexes within the acrylamide gel matrix. • In-gel protein denaturation followed by transfer of complexes to PVDF membrane, which allows the analysis of complexes' abundance using antibodies.

Sustainable and Flexible Energy Storage Devices: A Review

In recent years, the growing demand for increasingly advanced wearable electronic gadgets has been commonly observed. Modern society is constantly expecting a noticeable development in terms of smart functions, long-term stability, and long-time outdoor operation of portable devices. Excellent flexibility, lightweight nature, and environmental friendliness are no less important aspects of the choice of mobile electronics. Naturally, electronic devices need efficient portable power sources (batteries and supercapacitors) that meet the above-mentioned requirements. However, most of these power sources use plastic substrates for their manufacture. Hence, this review is focused on research attempts to shift energy storage materials toward sustainable and flexible components. We would like to introduce recent scientific achievements in the application of noncellulosic polysaccharides for flexible electrochemical energy storage devices as constituents in composite materials for both batteries and supercapacitors. In this review, we will summarize the introduction of biopolymers for portable power sources as components to provide sustainable as well as flexible substrates, a scaffold of current collectors, electrode binders, gel electrolyte matrices, separators, or binding scaffolds for whole devices.

Extremely Precise Blood-Plasma Separation from Whole Blood on a Centrifugal Microfluidic Disk (Lab-on-a-Disk) Using Separator Gel.

Due to the expansion of point-of-care devices, proposing a convenient and efficient method for blood-plasma separation would help with the use of point-of-care devices. Commercial microfluidic chips are only able to separate a limited amount of plasma, and the majority of these chips need an active valve system, which leads to increase manufacturing cost and complexity. In this research study, we designed a centrifugal microfluidic disk with a passive valve for ultra-accurate and efficient blood-plasma separation on a large scale (2-3 mL). The disk contained a separator gel, which, after applying the centrifugal force, separated the plasma and red blood cells. The passive valve worked based on the inertial force and was able to transfer more than 90% of the separated plasma to the next chamber. The results demonstrated that the separated plasma was 99.992% pure. This study compared the efficiency of the disk containing separating gel with the common lab-on-a-disk design for plasma separation. A comparison of the results showed that although the common lab-on-a-disk design could separate almost pure plasma as the disk contained separator gel, it could only transfer 60% of plasma to the next chamber.