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Immunoaffinity Column (immunoaffinity + column)
Selected AbstractsDETERMINATION OF AFLATOXIN CONTAMINATION IN OLIVES BY IMMUNOAFFINITY COLUMN USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHYJOURNAL OF FOOD QUALITY, Issue 2 2006CAVIT BIRCAN ABSTRACT Eighty-two whole black olive samples gathered from six different olive oil processing facilities were surveyed to determine levels of aflatoxins using immunoaffinity column extraction and reversed-phase high-performance liquid chromatography. Two different analytical procedures adopted for the analysis of aflatoxins were investigated for their suitability by spiking the blank olive samples with five different known levels of aflatoxins to determine which one had higher recovery rates. Although some of the olive samples had been exposed to adverse conditions, such as rain and high temperatures, none were found to contain aflatoxins at the determined detection limit. Although the samples were kept in high relative humidity (75%) and high temperature (30C) for 3 months and were tested at 1-month intervals, no aflatoxins were detected. In addition, the olives were inoculated on a potato dextrose agar medium and incubated for 7 days at 25C to characterize the microflora. Because there is no evidence of aflatoxins in fresh whole olives, the next step of processing the contaminated olives into olive oils and testing them for the aflatoxins was not pursued. [source] Elevated serum and cerebrospinal fluid levels of soluble human herpesvirus type 6 cellular receptor, membrane cofactor protein, in patients with multiple sclerosisANNALS OF NEUROLOGY, Issue 4 2001Samantha S. Soldan MS Membrane cofactor protein (CD46) is a member of a family of glycoproteins that are regulators of complement and prevent activation of complement on autologous cells. Recently, CD46 has been identified as the cellular receptor for human herpesvirus Type 6 (HHV-6). Elevated levels of soluble CD46 have been described in several autoimmune disorders and may be implicated in the pathogenesis of these diseases. As several reports have supported an association of HHV-6 and multiple sclerosis, it was of interest to compare levels of soluble CD46 in the sera of MS patients to that of healthy controls, other neurological disease controls, and other inflammatory disease controls. Using an immunoaffinity column comprised of immobilized monoclonal antibodies to CD46, serum levels of soluble CD46 were found to be significantly elevated in multiple sclerosis patients compared with healthy and other neurological disease controls. Moreover, multiple sclerosis patients who tested positive for HHV-6 DNA in serum had significantly elevated levels of soluble CD46 in their serum compared with those who were negative for HHV-6 DNA. A significant increase in soluble CD46 was also found in the serum of other inflammatory disease controls tested compared with healthy controls. Additionally, a significant correlation was demonstrated between levels of soluble CD46 in the serum and cerebrospinal fluid of multiple sclerosis patients. Collectively, these data suggest that elevated levels of soluble CD46 may contribute to the pathogenesis of inflammatory diseases, including MS. [source] Limitation of immunoaffinity column for the removal of abundant proteins from plasma in quantitative plasma proteomicsBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009Tomoko Ichibangase Abstract In plasma proteomics, before a proteome analysis, it is essential to prepare protein samples without high-abundance proteins, including albumin, via specific preparation techniques, such as immunoaffinity capture. However, our preliminary experiments suggested that functional changes with use alter the ability of the immunoaffinity column. Thus, in this study, to evaluate the changes of the removal ability of abundant proteins from plasma by the immunoaffinity column, plasma proteome analysis was performed for the long-term test for the reproducibility of the affinity column using the fluorogenic derivatization,liquid chromatography,tandem mass spectrometry method combined with an IgY column. The specific adsorption for albumin decreased with an increase in the number of the column usage before its expiration date. Moreover, it was demonstrated that hydrophobic high molecular weight compounds in plasma adsorbed onto the column materials surface contributed to the functional changes from specific immunoaffinity adsorption into hydrophobic interaction. These results suggested that, in quantitative plasma proteomics studies, it is important to keep in mind the risk of not only the nonselective loss but also the changes in the adsorption ability of the immunoafinity column. Copyright © 2008 John Wiley & Sons, Ltd. [source] Combined use of supported liquid membrane and solid-phase extraction to enhance selectivity and sensitivity in capillary electrophoresis for the determination of ochratoxin A in wineELECTROPHORESIS, Issue 7 2008Sara Almeda Abstract This paper proposes a novel strategy to enhance selectivity and sensitivity in CE, using supported liquid membrane (SLM) and off-line SPE simultaneously. The determination of ochratoxin A (OA) in wine has been used to demonstrate the potential of this methodology. In the SLM step, the donor phase (either a 20,mL volume of a standard solution at pH,1 or a wine sample at pH,8) was placed in a vial, where a micromembrane extraction unit accommodating the acceptor phase (1,mL water, pH,11) in its lumen was immersed. The SLM was constructed by impregnating a porous Fluoropore Teflon (PTFE) membrane with a water-immiscible organic solvent (octanol). In the off-line SPE step, the nonpolar sorbent (C-18, 4,mg) selectively retained the target ochratoxin, enabling small volumes of acceptor phase (1,mL) to be introduced. The captured analytes were eluted in a small volume of methanol (0.1,mL). This procedure resulted in sample cleanup and concentration enhancement. The method was evaluated for accuracy and precision, and its RSD found to be 5%. The LODs for OA in the standard solutions and wine samples were 0.5 and 30,,g/L, respectively. The results obtained demonstrate that SLM combined with off-line is a good alternative to the use of immunoaffinity columns prior to CE analysis. [source] Immuno-ultrafiltration as a new strategy in sample clean-up of aflatoxinsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 10 2009Elisabeth Viktoria Reiter Abstract The present paper describes the development of a new clean-up strategy for the analysis of aflatoxins (AFs) in food. The sample preparation method is based on immuno-ultrafiltration (IUF) which, in contrast to immunoaffinity chromatography, makes use of antibodies in free form. After selecting an appropriate ultrafiltration (UF) device and optimizing different operation conditions the IUF method was applied to the clean-up of maize and rice. Quantification of AFs was carried out by HPLC and fluorescence detection, after postcolumn derivatization in a Kobracell. The IUF method was shown to be as selective as sample clean-up using commercial immunoaffinity columns. Recovery rates and RSD for the AFs G2, G1, B2 and B1 in spiked rice were found to be 76 ± 3, 76 ± 2, 83 ± 5 and 99 ± 14%, respectively. The analysis of a FAPAS (food analysis performance assessment scheme) maize material resulted in AFs concentrations which were in the range assigned by the producer of the reference material. [source] In-house validation of a high-performance liquid chromatography analytical method for quantification of ochratoxin A in unfermented grape juiceJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2007Ma Teresa Murillo Abstract A validated high-performance liquid chromatography (HPLC) method with fluorescence detection for the quantitative analysis of ochratoxin A (OTA) in unfermented grape juice is described. Five millilitres of unfermented grape juice was mixed with 45 mL of PBS, and the pH was adjusted to 7.2. Then the mixture was filtered under vacuum through a glass microfibre filter and cleaned up with immunoaffinity columns prior to analysis by HPLC. Validation of the analytical method was based on the following criteria: selectivity, linearity, limit of detection and quantification, precision (within-day and between-day variability) and recovery and uncertainty estimation. Detection and quantification limits obtained were 0.02 µg L,1 and 0.05 µg L,1 respectively. The percentage recovery was 91.5% (RSD = 3.9). This method was applied to the measurement of 30 veraison stage unfermented grape juice samples. Copyright © 2007 Society of Chemical Industry [source] | ||||||||||