• July 14, 2024

Compare Pcr lab reagents for research

Suppliers for Lab polyclonals

Our used recombinants in Pubmed.

Read More

Compare Pcr lab reagents for research

Suppliers for Lab monoclonals

Our used polyclonals in Pubmed.

Read More

recombinant Lab Reagents for Research

Promoted Lab TESTs

Our used monoclonals in Pubmed.

Read More

Nanotheranostics: A powerful next-generation solution to tackle hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an epidemic burden and remains highly prevalent worldwide. The significant mortality rates of HCC are largely due to the tendency of late diagnosis and the multifaceted, complex nature of treatment. Meanwhile, current therapeutic modalities such as liver resection and transplantation are only effective for resolving early-stage HCC. Hence, alternative approaches are required to improve detection and enhance the efficacy of current treatment options. Nanotheranostic platforms, which utilize biocompatible nanoparticles to perform both diagnostics and targeted delivery, has been considered a potential approach for cancer management in the past few decades. Advancement of nanomaterials and biomedical engineering techniques has led to rapid expansion of the nanotheranostics field, allowing for more sensitive and specific diagnosis, real-time monitoring of drug delivery, and enhanced treatment efficacies across various malignancies. The focus of this review is on Gentaur gelONE & gelONE+ the applications of nanotheranostics for HCC. The review first explores the current epidemiology and the commonly encountered obstacles in HCC diagnosis and treatment. It then presents the current technological and functional advancements in nanotheranostic technology for cancer in general, and then specifically explores the use of nanotheranostic modalities as a promising option to address the key challenges present in HCC management.

Immune Checkpoint LAG3 and Its Ligand FGL1 in Cancer

LAG3 is the most promising immune checkpoint next to PD-1 and CTLA-4. High LAG3 and FGL1 expression boosts tumor growth by inhibiting the immune microenvironment. This review comprises four sections presenting the structure/expression, interaction, biological effects, and clinical application of LAG3/FGL1. D1 and D2 of LAG3 and FD of FGL1 are the LAG3-FGL1 interaction domains. LAG3 accumulates on the surface of lymphocytes in various tumors, but is also found in the cytoplasm in non-small cell lung cancer (NSCLC) cells. FGL1 is found in the cytoplasm in NSCLC cells and on the surface of breast cancer cells. The LAG3-FGL1 interaction mechanism remains unclear, and the intracellular signals require elucidation. LAG3/FGL1 activity is associated with immune cell infiltration, proliferation, and secretion. Cytokine production is enhanced when LAG3/FGL1 are co-expressed with PD-1. IMP321 and relatlimab are promising monoclonal antibodies targeting LAG3 in melanoma. The clinical use of anti-FGL1 antibodies has not been reported. Finally, high FGL1 and LAG3 expression induces EGFR-TKI and gefitinib resistance, and anti-PD-1 therapy resistance, respectively. We present a comprehensive overview of the role of LAG3/FGL1 in cancer, suggesting novel anti-tumor therapy strategies.

Futility in Transcatheter Aortic Valve Implantation: A Search for Clarity

Although transcatheter aortic valve implantation (TAVI) has revolutionised the landscape of treatment for aortic stenosis, there exists a cohort of patients where TAVI is deemed futile. Among the pivotal high-risk trials, one-third to half of patients either died or received no symptomatic benefit from the procedure at 1 year. Futility of TAVI results in the unnecessary exposure of risk for patients and inefficient resource utilisation for

healthcare services. Several cardiac and extra-cardiac conditions and frailty increase the risk of mortality despite TAVI. read more

Read More

Self-Sustainable Wearable Textile Nano-Energy Nano-System (NENS) for Next-Generation Healthcare Applications

Wearable electronics presage a future in which healthcare monitoring and rehabilitation are enabled beyond the limitation of hospitals, and self-powered sensors and energy generators are key prerequisites for a self-sustainable wearable system. A triboelectric nanogenerator (TENG) based on textiles can be an optimal option for scavenging low-frequency and irregular waste energy from body motions as a power source for self-sustainable systems. However, the low output of most textile-based TENGs (T-TENGs) has hindered its way toward practical applications. In this work, a facile and universal strategy to enhance the triboelectric output is proposed by integration of a narrow-gap TENG textile with a high-voltage diode and a textile-based switch. The closed-loop current of the diode-enhanced textile-based TENG (D-T-TENG) can be increased by 25 times. The soft, flexible, and thin characteristics of the D-T-TENG enable a moderate output even as it is randomly scrunched. Furthermore, the enhanced current can directly stimulate rat muscle and nerve. In addition, the capability of the D-T-TENG as a practical power source for wearable sensors is Gentaur Bluetooth Humidity/Temperature Monitoring demonstrated by powering Bluetooth sensors embedded to clothes for humidity and temperature sensing. Looking forward, the D-T-TENG renders an effective approach toward a self-sustainable wearable textile nano-energy nano-system for next-generation healthcare applications.

Temperature and Humidity Calibration of a Low-Cost Wireless Dust Sensor for Real-Time Monitoring

This paper introduces the design, calibration, and validation of a low-cost portable sensor for the real-time measurement of dust particles within the environment. The proposed design consists of low hardware cost and calibration based on temperature and humidity sensing to achieve accurate processing of airborne dust density.

  • Using commercial particulate matter sensors, a highly accurate air quality monitoring sensor was designed and calibrated using real world variations in humidity and temperature for indoor and outdoor applications.
  • Furthermore, to provide a low-cost secure solution for real-time data transfer and monitoring, an onboard Bluetooth module with AES data encryption protocol was implemented.
  • The wireless sensor was tested against a Dylos DC1100 Pro Air Quality Monitor, as well as an Alphasense OPC-N2 optical air quality monitoring sensor for accuracy. The sensor was also tested for reliability by comparing the sensor to an exact copy of itself under indoor and outdoor conditions.
  • It was found that accurate measurements under real-world humid and temperature varying and dynamically changing conditions were achievable using the proposed sensor when compared to the commercially available sensors.
  • In addition to accurate and reliable sensing, this sensor was designed to be wearable and perform real-time data collection and transmission, making it easy to collect and analyze data for air quality monitoring and real-time feedback in remote health monitoring applications.
  • Thus, the proposed device achieves high-quality measurements at lower-cost solutions than commercially available wireless sensors for air quality.
  • read more

    Read More

    Advection-enhanced kinetics in microtiter plates for improved surface assay quantitation and multiplexing capabilities

    Surface assays such as ELISA are pervasive in clinics and research and predominantly standardized in microtiter plates (MTP). MTPs provide many advantages but are often detrimental to surface assay efficiency due to inherent mass transport limitations. Microscale flows can overcome these and largely improve assay kinetics. However, the disruptive nature of microfluidics with existing labware and protocols has narrowed its transformative potential. We present WellProbe, a novel microfluidic concept compatible with MTPs. With it, we show that immunoassays become more sensitive at low concentrations (up to 9× signal improvement in 12x less time), richer in information with 3-4 different kinetic conditions, and can be used to estimate kinetic parameters, minimize washing steps and non-specific binding, and identify compromised results. We further multiplex single-well assays combining WellProbe’s kinetic regions with tailored microarrays. Finally, we demonstrate our system in a context of immunoglobulin subclass evaluation, increasingly regarded as clinically relevant.

    Automation for Life Science Laboratories

    The automation of processes in all areas of the life sciences will continue to increase in the coming years due to an ever increasing number of samples to be processed Gentaur Labware, an increasing need to protect laboratory personnel from infectious material and increasing cost pressure. Depending on the requirements of the respective application, different concepts for automation systems are available, which have a different degree of automation with regard to data handling, transportation tasks, and the processing of the samples.
    • Robots form a central component of these automation concepts. Classic stationary robots from the industrial sector will increasingly be replaced by new developments in the field of light-weight robots.
    • In addition, mobile robots will also be of particular importance in the automation of life science laboratories in the future, especially for transportation tasks between different manual and (partially) automated stations.
    • With an increasing number of different, highly diverse processes, the need for special devices and system components will also increase.
    • This applies to both, the handling of the labware and the processing of the samples. In contrast to previous automation strategies with a highly parallel approach, future developments will increasingly be characterized by individual sample handling.

    Fluorescence-based Single-cell Analysis of Whole-mount-stained and Cleared Microtissues and Organoids for High Throughput Screening

    Three-dimensional (3D) cell culture, especially in the form of organ-like microtissues (“organoids”), has emerged as a novel tool potentially mimicking human tissue biology more closely than standard two-dimensional culture. Typically, tissue sectioning is the standard method for immunohistochemical analysis. However, it removes cells from their native niche and can result in the loss of 3D context during analyses.
    • Automated workflows require parallel processing and analysis of hundreds to thousands of samples, and sectioning is mechanically complex, time-intensive, and thus less suited for automated workflows.
    • Here, we present a simple protocol for combined whole-mount immunostaining, tissue-clearing, and optical analysis of large-scale (approx. 1 mm) 3D tissues with single-cell level resolution.
    • While the protocol can be performed manually, it was specifically designed to be compatible with high-throughput applications and automated liquid handling systems.
    • This approach is freely scalable and allows parallel automated processing of large sample numbers in standard labware.
    • We have successfully applied the protocol to human mid- and forebrain organoids, but, in principle, the workflow is suitable for a variety of 3D tissue samples to facilitate the phenotypic discovery of cellular behaviors in 3D cell culture-based high-throughput screens.
    • Graphic abstract: Automatable organoid clearing and high-content analysis workflow and timeline.

    Gold-Polyoxoborates Nanocomposite Prohibits Adsorption of Bacteriophages on Inner Surfaces of Polypropylene Labware and Protects Samples from Bacterial and Yeast Infections

    Bacteriophages (phages) are a specific type of viruses that infect bacteria. Because of growing antibiotic resistance among bacterial strains, phage-based therapies are becoming more and more attractive. The critical problem is the storage of bacteriophages. Recently, it was found that bacteriophages might adsorb on the surfaces of plastic containers, effectively decreasing the titer of phage suspensions. Here, we showed that a BOA nanocomposite (gold nanoparticles embedded in polyoxoborate matrix) deposited onto the inner walls of the containers stabilizes phage suspensions against uncontrolled adsorption and titer decrease. Additionally, BOA provides antibacterial and antifungal protection. The application of BOA assures safe and sterile means for the storage of bacteriophages.

    Adsorption of bacteriophages on polypropylene labware affects the reproducibility of phage research

    Hydrophobicity is one of the most critical factors governing the adsorption of molecules and objects, such as virions, on surfaces. Even moderate change of wetting angle of plastic surfaces causes a drastic decrease ranging from 2 to 5 logs of the viruses (e.g., T4 phage) in the suspension due to adsorption on polymer vials’ walls.
    • The effect varies immensely in seemingly identical containers but purchased from different vendors. Comparison of glass, polyethylene, polypropylene, and polystyrene containers revealed a threshold in the wetting angle of around 95°: virions adsorb on the surface of more hydrophobic containers, while in more hydrophilic vials, phage suspensions are stable.
    • The polypropylene surface of the Eppendorf-type and Falcon-type can accommodate from around 108 PFU/ml to around 1010 PFU/ml from the suspension.
    • The adsorption onto the container’s wall might result in complete scavenging of virions from the bulk. We developed two methods to overcome this issue.
    • The addition of surfactant Tween20 and/or plasma treatment provides a remedy by modulating surface wettability and inhibiting virions’ adsorption.
    • Plastic containers are essential consumables in the daily use of many bio-laboratories.
    • Thus, this is important not only for phage-related research (e.g., the use of phage therapies as an alternative for antibiotics) but also for data comparison and reproducibility in the field of biochemistry and virology.

    Resonant acoustic rheometry for non-contact characterization of viscoelastic biomaterials read more

    Read More

    Duohua huangjing (Polygonatum cyrtonema Hua) seedling basal rot caused by Fusarium redolens in China

    Duohua huangjing (Polygonatum cyrtonema Hua) seedling basal stem rot caused by Fusarium redolens in China Tao Tang1, Fanfan Wang1, Jie Guo1, Xiaoliang Guo1, Yuanyuan Duan1,Jingmao You1* 1 Institute of Chinese Herbal Medicines, Hubei Academy of Agricultural Sciences, Enshi, 445000, China. Duohua huangjing (Polygonatum cyrtonema Hua), a herbal medicine, that is mostly planted in several provinces in China. In April 2020, severe diseases with about 40% seedling losse was found in the Huangjing seedling base in Shiyan city, Hubei province. The symptoms included softening and decay of the roots and stem bases, a progressive yellowing and wilting of leaves, and finally being completely rotted. Small pieces of symptomatic stems (0.5 cm in length) and leaves (0.5 × 0.5 cm in size) were surface sterilized with 75% ethanol for 30 s, followed by 0.1% HgCl2 for 1 min, rinsed three times with sterile water, and then dried with sterilized absorbent paper. The sections were placed on potato dextrose agar (PDA) medium containing 10 µg/ml of ampicillin and incubated at 25°C in the dark. After 3 days incubation, eight isolates with the same colony morphology were sub-cultured and purified by hyphal tip isolation. Macroconidia were sickle-shaped, 15.8 – 32.3 × 3.1 – 5.6 μm (n = 25), and three to five septate. Microconidia were oval or kidney-shaped, 5.2 – 11.4 × 2.0 – 3.2 μm (n = 25), and zero to one septate. To confirm the identity of the pathogen, molecular identification was performed with strain HJCD1. Following DNA extraction, PCR was performed using the TSINGKE 2×T5 Direct PCR Mix kit. Target areas of amplification were the internal transcribed spacer (ITS) and translation elongation factor 1α (TEF-1α) using ITS1/4 (White et al. 1990) , EF1/EF2 (Taylor et al. 2016), respectively. Following BLAST searches and phylogenetic reconstruction, the ITS region (GenBank MW485770.1) showed 99% identity with those of Fusarium redolens in GenBank (KU350713.1) and the TEF-1α (GenBank MW503930.1) showed 100% identity with F. redolens GenBank (MK922537.1). Pathogenicity tests were performed to fulfill Koch’s postulates. Huangjing seedlings were rinsed with sterile water, wiped clean with sterile absorbent paper, and transferred to a tray covered with wet filter paper to maintain high humidity. The mycelial piugs of F. redolens HJCD1 were inoculated onto the surface of leaves and basal stems. Controls were inoculated with sterile PDA plugs. The inoculated seedlings were sealed with plastic wrap, and then cultivated in a 25 ℃ growth chamber with 16 h of light per day. The pathogen-inoculated plants Gentaur PCR Filter Tips exhibited etiolation and typical wilt symptoms after 4 days, whereas no symptoms were observed in the control plants. F. redolens was reisolated from the infected tissues, and colony morphology and ITS sequence of re-isolates were same as that of HJCD1. The pathogen has been reported previously in american ginseng in China (Fan et al. 2021), lentil in Pakistan (Rafique et al. 2020), and wild rocket in United Kingdom (Taylor et al. 2019). However, to the best of our knowledge, this is the first report of F. redolent causing seelding basal rot on Duohua huangjing in China. References: White, T. J., et al. 1990. Page 315 in: PCR

    Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA. Taylor, A., et al. 2016. Mol. Plant Pathol. 17:1032. https://doi.org/10.1111/mpp.12346 Fan, S. H., et al. 2021. Plant Dis. https://doi.org/10.1094/PDIS-11-19-2519-PDN Rafique, K., et al. 2020 read more

    Read More

    Use of equine sperm cryopreservation techniques as a conservation method of donkey germplasm

    The aim of this study was to test equine semen cryopreservation techniques for the conservation of donkey germplasm. Ejaculates of three male donkeys were used (n= 18; six ejaculates per donkey; six repetitions), collected by the artificial vagina method. To remove the seminal plasma (SP), the ejaculates were split and submitted to filtration or centrifugation methods. To assess the freezing method, each fraction were submitted to the automated system or the conventional system, and groups were formed: automated centrifuge (AC), automated filtrate (AF), conventional centrifuge (CC) and conventional filtrate (CF). After thawing (37°C/30 s), were analyzed the sperm kinetic parameters, integrity and functionality of the plasma membrane and mitochondrial membrane potential. Highest sperm concentration (P<0.05) was observed in the filtrate groups; the CF group presented lower (P<0.05) progressive motility and curvilinear velocity compared to the other groups; no difference was observed (P>0.05) among the groups for the membrane integrity and functionality, and mitochondrial membrane potential. Thus, centrifugation is the most indicated technique to remove donkey seminal plasma and the automated and conventional freezing methods Gentaur Centrifuges can be used in donkey semen conservation.

    Nitrogen resource recovery from mature leachate via heat extraction technology: An engineering project application

    A large pool of ammonia in mature leachate is challenging to treat with a membrane bioreactor system to meet the discharge Standard for Pollution Control on the Landfill Site of Municipal Solid Waste in China (GB 16889-2008) without external carbon source addition. In this study, an engineering leachate treatment project with a scale of 2,000 m3/d was operated to evaluate the ammonia heat extraction system (AHES), which contains preheat, decomposition, steam-stripping, ammonia recovery, and centrifuge dewatering. The operation results showed that NH3-N concentrations of raw leachate and treated effluent from an ammonia heat extraction system (AHES) were 1,305-2,485 mg/L and 207-541 mg/L, respectively. The ratio of COD/NH3-N increased from 1.40-1.84 to 7.69-28.00. Nitrogen was recovered in the form of NH4HCO3 by the ammonia recovery tower with the introduction of CO2, wherein the mature leachate can offer 37% CO2 consumption. The unit consumptions of steam and power were 8.0% and 2.66 kWh/m3 respectively, and the total operation cost of AHES was 2.06 USD per cubic metre of leachate. These results confirm that heat extraction is an efficient and cost-effective technology for the recovery of nitrogen resource from mature leachate.

    Field Determination of Phosphate in Environmental Water by Using a Hand-Powered Paper Centrifuge for Preconcentration and Digital Image Colorimetric Sensing

    Phosphate concentration in natural water has been used as a water quality indicator, as it is one of the major nutrients for aquatic plants. However, the traditional phosphomolybdenum blue (PMB) method has limited sensitivity for visual or camera-based detection, leading to underestimation of the phosphate concentration. We present an ultralow-cost, rapid field preconcentration and digital image colorimetric sensing of low-concentration phosphate method for water analysis. A novel hand-powered paper centrifuge (paperfuge) is used for sample preparation and preconcentration. This paperfuge is made of two circular paper discs and a string. Six centrifuge tubes (CTs) originally used as glue dispensing tips with a sample capacity of ∼230 μL, are loaded on the paperfuge. After sampling, phosphate in the water sample is reacted to form PMB. Then, the reacted sample is drawn into a CT using an autopipette before the CT bottom is sealed by glue. After Oasis HLB sorbents are added through the top of the CT, the CT top is also sealed with glue. The HLB sorbents adsorb PMB and are accumulated in the CT tip through centrifugation. The CT tips are cut and analyzed with the ImageJ software. It was found that the blue color intensity of sorbents is in a linear relationship to the phosphate concentration, with a linear range of 0-5 μM (r 2 = 0.9921) and limit of detection of 0.19 μM. In addition, this method has been applied to in-field water analysis. The results are in agreement with the standard PMB method.

    Pyridine-functional diblock copolymer nanoparticles synthesized via RAFT-mediated polymerization-induced self-assembly: effect of solution pH

    Polymerization-induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) polymerization has become widely recognized as a versatile and efficient strategy to prepare complex block copolymer nanoparticles with controlled morphology, size, and surface functionality. In this article, we report the preparation of cationic sterically-stabilized poly(2-vinylpyridine)-poly(benzyl methacrylate) (P2VP-PBzMA) diblock copolymer nanoparticles via RAFT-mediated PISA under aqueous emulsion polymerization conditions. It is demonstrated that the solution pH during PISA has a dramatic effect on the resulting P2VP-PBzMA nanoparticles, as judged by dynamic light scattering (DLS), disc centrifuge photosedimentometry (DCP) and transmission electron microscopy (TEM). Varying the solution pH results in the P2VP stabilizer having different solubilities due to protonation/deprotonation of the pyridine groups. This allows P2VP-PBzMA nanoparticles with tunable diameters to be prepared by altering the DP of the stabilizer (P2VP) and/or core-forming block (PBzMA), or simply by changing the solution pH for a fixed copolymer composition. For example, P2VP-PBzMA nanoparticles with larger diameters can be obtained at higher solution pH as the protonation degree of the P2VP stabilizer has a large effect on both the aggregation of polymer chains during the PISA process, and the resulting behavior of the diblock copolymer nanoparticles. Changing the dispersion pH post-polymerization has a relatively limited effect on particle diameter. Furthermore, aqueous electrophoresis studies indicate that these P2VP-PBzMA nanoparticles had good colloidal stability and high cationic charge (>30 mV) below pH 5 and can be dispersed readily over a wide pH range.

    Simultaneous determination of 36 hypotensive drugs in fingerprints by ultra performance liquid chromatography-triple quadrupole composite linear ion trap mass spectrometry read more

    Read More

    Malva parviflora Leaves Mucilage: An Eco-Friendly and Sustainable Biopolymer with Antioxidant Properties

    Malva parviflora L. is an edible and medicinal herb containing mucilaginous cells in its leaves. Mucilage obtained from M. parviflora leaves (MLM) was extracted in distilled water (1:10 w/v) at 70 °C followed by precipitation with alcohol. Preliminary phytochemical tests were performed to assess the purity of the extracted mucilage. Results showed that the yield of mucilage was 7.50%, and it was free from starch, alkaloids, glycosides, saponins, steroids, lipids and heavy metals. MLM had 16.19% carbohydrates, 13.55% proteins and 4.76% amino acids, which indicate its high nutritional value. Physicochemical investigations showed that MLM is neutral and water-soluble, having 5.84% moisture content, 15.60% ash content, 12.33 swelling index, 2.57 g/g water-holding capacity and 2.03 g/g oil-binding capacity.

  • The functional properties, including emulsion capacity, emulsion stability, foaming capacity and stability increased with increased concentrations.
  • Micromeritic properties, such as bulk density, tapped density, Carr’s index, Hausner ratio, and angle of repose, were found to be 0.69 g/cm3, 0.84 g/cm3, 17.86%, 1.22 and 28.5, respectively. Scanning electron microscopy (SEM) showed that MLM is an amorphous powder possessing particles of varying size and shape; meanwhile, rheological studies revealed the pseudoplastic behavior of MLM.
  • The thermal transition process of MLM revealed by a differential scanning calorimetry (DSC) thermogram, occurring at a reasonable enthalpy change (∆H), reflects its good thermal stability. The presence of functional groups characteristic of polysaccharides was ascertained by the infrared (IR) and gas chromatography/mass spectrometry (GC/MS) analyses.
  • GC revealed the presence of five neutral monosaccharides; namely, galactose, rhamnose, arabinose, glucose and mannose, showing 51.09, 10.24, 8.90, 1.80 and 0.90 mg/g of MLM, respectively. Meanwhile, galacturonic acid is the only detected acidic monosaccharide, forming 15.06 mg/g of MLM.
  • It showed noticeable antioxidant activity against the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical with an IC50 value of 154.27 µg/mL. It also prevented oxidative damage to DNA caused by Gentaur Gel Documentation System the Fenton reagent, as visualized in gel documentation system.
  • The sun protection factor was found to be 10.93 ± 0.15 at 400 µg/mL. Thus, MLM can be used in food, cosmetic and pharmaceutical industry and as a therapeutic agent due to its unique properties.
  • read more

    Read More

    Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges

    Emission of light by matter can occur through a variety of mechanisms. When it results from an electronically excited state of a species produced by a chemical reaction, it is called chemiluminescence (CL). The phenomenon can take place both in natural and artificial chemical systems and it has been utilized in a variety of applications. In this review, we aim to revisit some of the latest CL applications based on direct and indirect production modes. The characteristics of the chemical reactions and the underpinning CL mechanisms are thoroughly discussed in view of studies from the very recent bibliography. Different methodologies aiming at higher CL efficiencies are summarized and presented in detail, including CL type and scaffolds used in each study. The CL role in the development of efficient therapeutic platforms is also discussed in relation to the Reactive Oxygen Species (ROS) and singlet oxygen (1O2) produced, as final products. Moreover, recent research results from our team are included regarding the behavior of commonly used photosensitizers upon chemical activation under Gentaur Chemiluminescence Imaging System CL conditions. The CL prospects in imaging, biomimetic organic and radical chemistry, and therapeutics are critically presented in respect to the persisting challenges and limitations of the existing strategies to date.

    A Novel Brighter Bioluminescent Fusion Protein Based on ZZ Domain and Amydetes vivianii Firefly Luciferase for Immunoassays

    Immunoassays are widely used for detection of antibodies against specific antigens in diagnosis, as well as in electrophoretic techniques such as Western Blotting. They usually rely on colorimetric, fluorescent or chemiluminescent methods for detection. Whereas the chemiluminescence methods are more sensitive and widely used, they usually suffer of fast luminescence decay. Here we constructed a novel bioluminescent fusion protein based on the N-terminal ZZ portion of protein A and the brighter green-blue emitting Amydetes vivianii firefly luciferase. In the presence of D-luciferin/ATP assay solution, the new fusion protein displays higher bioluminescence activity, is very thermostable and produces a sustained emission (t1/2 > 30 min). In dot blots, we could successfully detect rabbit IgG against firefly luciferases, Limpet Haemocyanin, and SARS-CoV-2 Nucleoprotein (1-250 ng), as well as the antigen bound antibodies using either CCD imaging, and even photography using smartphones. Using CCD imaging, we could detect up to 100 pg of SARS-CoV-2 Nucleoprotein. Using this system, we could also successfully detect firefly luciferase and SARS-CoV-2 nucleoprotein in Western Blots (5-250 ng). Comparatively, the new fusion protein displays slightly higher and more sustained luminescent signal when compared to commercial HRP-labeled secondary antibodies, constituting a novel promising alternative for Western Blotting and immunoassays.

    Long-Lasting Luminol Chemiluminescence Emission with 1,10-Phenanthroline-2,9-dicarboxylic Acid Copper(II) Complex on Paper

    As most of the known systems are flashtype, long-lasting chemiluminescence (CL) emissions are extremely needed for the application of cold light sources, accurate CL quantitative analysis, and biological mapping. In this work, the flashtype system of luminol was altered to a long lasting CL system just because of the paper substrate. The Cu(II)-based organic complex was loaded on the paper surface, which can trigger luminol-H2O2 to produce a long lasting CL emission for over 30 min. By using 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand, a hexacoordinated Cu(II)-based organic complex was synthesized by the simple freeze-drying method. It is interesting that the complex morphology can be controlled by adding different amounts of water in the synthesizing procedure. The complex with a certain size can be definitely trapped in the pores of the cellulose.
    • Then, slow diffusion, which can be attributed to the long lasting CL emission, was produced. With the high catalytic activity of the complex, reactive oxygen species from H2O2 was generated and was responsible for the high CL intensity.
    • By using the paper substrate, the flash-type luminol system can be easily transferred to the long-duration CL system without any extra reagent.
    • This long-lasting emission system was used for hydrogen sulfide detection by the CL imaging method.
    • This paper-based sensor has great potential for CL imaging in the clinical field in the future.

    Insight into the Ozone-Assisted Low-Temperature Combustion of Dimethyl Ether by Means of Stabilized Cool Flames

    The low-temperature combustion kinetics of dimethyl ether (DME) were studied by means of stabilized cool flames in a heated stagnation plate burner configuration using ozone-seeded premixed flows of DME/O2. Direct imaging of CH2O* chemiluminescence and laser-induced fluorescence of CH2O were used to determine the flame front positions in a wide range of lean and ultra-lean equivalence ratios and ozone concentrations for two strain rates. The temperature and species mole fraction profiles along the flame were measured by coupling thermocouples, gas chromatography, micro-chromatography, and quadrupole mass spectrometry analysis. A new kinetic model was built on the basis of the Aramco 1.3 model, coupled with a validated submechanism of O3 chemistry, and was updated to improve the agreement with the obtained experimental results and experimental data available in the literature. The main results show the efficiency of the tested model to predict the flame front position and temperature in every tested condition, as well as the importance of reactions typical of atmospheric chemistry in the prediction of cool flame occurrence. The agreement on the fuel and major products is overall good, except for methanol, highlighting some missing kinetic pathways for the DME/O2/O3 system, possibly linked to the direct addition of atomic oxygen on the fuel radical, modifying the product distribution after the cool flame.

    Advanced image analysis-based evaluation of protein antibody microarray chemiluminescence signal improves glioma type identification by blood serum proteins concentrations read more

    Read More