![]() Bienzymatic analytical microreactors for glucose, lactate, ethanol, galactose and l-amino acid monitoring in cell culture media [An article from: Analytica Chimica Acta] $10.95 This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: A new alternative method for bioprocess monitoring based on bienzymatic analytical microreactors integrated in a flow injection analysis (FIA) system is described. Glucose-, alcohol-, lactate-, galactose- and l-amino acid oxidases (GO, AO, LacO, GalO and LAAO) and horseradish peroxidase (HRP) are immobilized on controlled pore glass (CPG) and used for the development of glucose, ethanol, lactate, galactose and amino acid sensors. The analytical methodology is based on HRP catalysed reaction of hydrogen peroxide produced by oxidases with phenol-4-sulfonic acid and 4-aminoantipyrine. The immobilized enzymes are characterized and used for preparation of the packed bed analytical microreactors. Shelf life and operational stability of the microeactors are determined. GO/HRP, AO/HRP and LAAO/HRP microreactors showed excellent shelf life, they could be stored and reused for more than 6 months with no or very little activity loss, while GalO/HRP and LacO/HRP could be stored for shorter periods of time (10-20 days). Operational stability of GO and LacO microreactors was very good: an equivalent to 16,900 FIA injections of 25@ml to a LacO microreactor resulted in loss of half of its activity, immobilized GO was so stable that it was impossible to evaluate enzyme halflife. Immobilized GalO and LAAO lose their operational activity much faster: approximately 1400 and 8000 FIA injections of the respective substrate solution in a FIA set-up resulted in 50% activity loss. The methods with all the described microreactors were successfully validated using off-line samples from S. cerevisiae, E. coli and mesenchymal stem cell cultures with HPLC as the reference method. od. ![]() Vital Nutrients MCP (Modified Citrus Pectin) 360g $123.90 MCP (Modified Citrus Pectin), also known as fractionated pectin, is a complex polysaccharide obtained from the peel and pulp of citrus fruits. Modified citrus pectin in rich in short galactose carbohydrate chain residues. MCP helps to maintain normal cell and tissue health and promotes healthy immune system function. ![]() A galactose polyacrylate-based hydrogel scaffold for the detection of cholera toxin and staphylococcal enterotoxin B in a sandwich immunoassay format [An article from: Analytica Chimica Acta] $10.95 This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: A galactoside-based polyacrylate hydrogel was used as a scaffold to immobilize antibodies for the development of a sandwich immunoassay to detect cholera toxin (CT) and staphylococcal enterotoxin B (SEB). The hydrogel possesses large pores and simulates a solution-like environment allowing easy penetration of large biomolecules. Highly crosslinked hydrogels containing pendant amine or carboxyl functionalities were polymerized through a free-radical polymerization process. Covalent crosslinking of the antibodies on hydrogel films was accomplished using a homobifunctional crosslinker or carbodiimide chemistry. Utilizing the two different crosslinking methodologies, our results demonstrated the effectiveness of repetitive additions of crosslinker reactant into a single location on the gel surface. This approach in fact increased the amount of immobilized antibody. Patterned arrays of the immobilized antibodies for sandwich immunoassay development were achieved using a PDMS template containing micro-channels. This template provided a suitable means for applying reagents in multiple cycles. Fluorescence and three-dimensional (3D) imaging by confocal microscopy and laser scanning confocal microscopy of Cy3-labeled anti-CT and/or Cy3-anti-SEB tracer molecules provided qualitative and quantitative measurements on the efficiency of protein immobilization, detection sensitivity and signal-to-noise ratios. As a result of using the galactose polyacrylate-base hydrogel as a platform for immunoassay development, we have successfully been able to achieve low limits of detection for SEB and cholera toxins (1.0ngmL^-^1). Repetitive additions (>3 cycles) of the crosslinker and antibody have also shown a dramatic increase in the immobilization of antibody resulting in improved immunoassay sensitivity. Fluorescence signal-to-noise ratios using the hydrogel-based immunoassays have been observed as high a 40:1. ![]() A @b-galactose-specific lectin isolated from the marine worm Chaetopterus variopedatus possesses anti-HIV-1 activity [An article from: Comparative Biochemistry and Physiology, Part C] $8.95 This digital document is a journal article from Comparative Biochemistry and Physiology, Part C, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: A 30 kDa @b-galactose-specific lectin named CVL was isolated from the polychaete marine worm Chaetopterus variopedatus (Annelida) and its anti-HIV-1 activity in vitro was determined. Results showed that CVL inhibited cytopathic effect induced by HIV-1 and the production of viral p24 antigen. The EC"5"0 values were 0.0043 and 0.057 @mM, respectively. Time-of-addition analysis of anti-HIV-1 activity indicated its action was at the early stage of virus replication. CVL could blocked the cell-to-cell fusion process of HIV infected and uninfected cells with an EC"5"0 of 0.073 @mM. The inhibition of HIV-1 entry into host cells was demonstrated by using fluorescence-based real-time quantify PCR. At CVL concentration of 0.33 @mM and 0.07 @mM, 86% and 21% virus attachment were blocked, respectively. The anti-HIV-1 action of CVL might relate to blockade of HIV-1 entry into cells. lls. |
|