A simple, fast, and highly sensitive direct competitive enzyme-linked immunosorbent assay (ELISA) based on bovine serum albumin (BSA) antigen labeled amine-terminated silicon dioxide (SiO-NH-BSA) nanoparticles was developed to determine residual BSA in vaccines. As nano-ELISA using nanomaterials with a very high surface-to-volume ratio has emerged as a promising strategy, SiO-NH-BSA nanoparticles were prepared in this study by the coupling of BSA to SiO nanoparticles modified with amidogen, followed by the quantification of BSA via a direct competitive binding of BSA-antigen-labeled SiO nanoparticles to anti-BSA antibody conjugated with horseradish peroxidase. The validation study showed that the linear range of this method was from 1 to 90 ng/mL (r = 0.998) and the limit of detection was 0.67 ng/mL. The intra-assay and interassay coefficients of variation were less than 10% at three concentrations (10, 40, and 70 ng/mL), and the recovery was 92.4%, indicating good specificity. As a proof of principle, this new method was applied in the analysis of residual BSA in five different vaccines. Bland-Altman plots revealed that there was no significant difference in the accuracy and precision between our new method and the most commonly used sandwich ELISA. From the results taken together, the new method developed in this study is more sensitive and facile with lower cost and thus demonstrated potential to be applied in the quality control of biological products. Graphical Abstract Illustration of the procedures of the direct competitive enzyme immunoassay.
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Proc Natl Acad Sci U S A
February 2025
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Swansea, Wales SA2 8PP, United Kingdom.
Large herbivores are in decline in much of the world, including sub-Saharan Africa, and true apex carnivores like the lion () decline in parallel with their prey. As a consequence, competitively subordinate carnivores like the African wild dog () are simultaneously experiencing a costly reduction in resources and a beneficial reduction in dominant competitors. The net effect is not intuitively obvious, but wild dogs' density, survival, and reproduction are all low in areas that are strongly affected by prey depletion.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Psychology, University of Liverpool, Liverpool L69 7ZA, United Kingdom.
Funding of curiosity-driven science is the lifeblood of scientific and technological innovation. Various models of funding allocation became institutionalized in the 20th century, shaping the present landscape of research funding. There are numerous reasons for scientists to be dissatisfied with current funding schemes, including the imbalance between funding for curiosity-driven and mission-directed research, regional and country disparities, path-dependency of who gets funded, gender and race disparities, low inter-reviewer reliability, and the trade-off between the effort and time spent on writing or reviewing proposals and doing research.
View Article and Find Full Text PDFEstablishing the anterior-posterior body axis is a fundamental process during embryogenesis, and the fruit fly, , provides one of the best-known case studies of this process. In Drosophila, localized mRNA of serves as anterior determinant (AD). Bicoid engages in a concentration-dependent competition with nucleosomes and initiates symmetry-breaking along the AP axis by promoting chromatin accessibility at the loci of transcription factor (TF) genes that are expressed in the anterior of the embryo.
View Article and Find Full Text PDFChem Sci
January 2025
J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University College Station TX 77843 USA
This perspective work examines the current advancements in integrated CO capture and electrochemical conversion technologies, comparing the emerging methods of (1) electrochemical reactive capture (eRCC) though amine- and (bi)carbonate-mediated processes and (2) direct (flue gas) adsorptive capture and conversion (ACC) with the conventional approach of sequential carbon capture and conversion (SCCC). We initially identified and discussed a range of cell-level technological bottlenecks inherent to eRCC and ACC including, but not limited to, mass transport limitations of reactive species, limitation of dimerization, impurity effects, inadequate generation of CO to sustain industrially relevant current densities, and catalyst instabilities with respect to some eRCC electrolytes, amongst others. We followed this with stepwise perspectives on whether these are considered intrinsic challenges of the technologies - otherwise recommendations were disclosed where appropriate.
View Article and Find Full Text PDFIn confluent cell monolayers, patterns of cell forces and motion are systematically altered near topological defects in cell shape. In turn, defects have been proposed to alter cell density, extrusion, and invasion, but it remains unclear how the defects form and how they affect cell forces and motion. Here, we studied +1/2 defects, and, in contrast to prior studies, we observed both tail-to-head and head-to-tail defect motion occurring at the same time in the same cell monolayer.
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