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Immunoassay
Kinds of Immunoassay Terms modified by Immunoassay Selected AbstractsUltrasensitive Eletrogenerated Chemiluminescence Immunoassay by Magnetic Nanobead AmplificationELECTROANALYSIS, Issue 3 2010Mingyue Li Abstract An ultrasensitive electrogenerated chemiluminescence (ECL) immunoassay was proposed by using magnetic nanobeads (MNBs) as the carrier of ECL labels for ECL emission amplification. Carcinoembryonic antigen (CEA) and MNBs were initially immobilized on a platform in 1,:,1 molar ratio via sandwich immunoreaction. Subsequently, the MNBs were released from the platform and labeled with Ru(bpy)32+ species. After the MNBs with Ru(bpy)32+ were immobilized on an Au electrode, ECL of the Ru(bpy)32+ was measured for CEA determination. A linear relation between the ECL intensity and CEA concentration was obtained in a range of 1×10,14 to 3×10,13,mol/L (2.0 to 60,pg/mL) with a limit of detection of 8.0×10,15,mol/L (1.6,pg/mL). [source] Electrochemical Immunoassay for Carbohydrate Antigen-125 Based on Polythionine and Gold Hollow Microspheres Modified Glassy Carbon ElectrodesELECTROANALYSIS, Issue 17 2007Xiao-Hong Fu Abstract A new electrochemical immunosensor for the detection of carbohydrate antigen-125 (CA125), a carcinoma antigen, was developed by immobilization CA125 antibody (anti-CA125) on gold hollow microspheres and porous polythionine (PTH) modified glassy carbon electrodes (GCE). The gold hollow microspheres provided a biocompatible microenvironment for proteins, and greatly amplified the coverage of anti-CA125 molecules on the electrode surface. The performance and factors influencing the immunosensor were investigated in detail. The detection is based on the current change before and after the antigen-antibody interaction. Under optimal conditions, the amperometric changes were proportional to CA125 concentration ranging from 4.5 to 36.5,U/mL with a detection limit of 1.3,U/mL (at 3,). The CA125 immunosensor exhibited good precision, high sensitivity, acceptable stability, accuracy and reproducibility. The as-prepared immunosensors were used to analyze CA125 in human serum specimens. Analytical results suggest that the developed immunoassay has a promising alternative approach for detecting CA125 in the clinical diagnosis. [source] Immunosensors: (Ionic-Liquid-Doped Polyaniline Inverse Opals: Preparation, Characterization, and Application for the Electrochemical Impedance Immunoassay of Hepatitis B Surface Antigen) Adv.ADVANCED FUNCTIONAL MATERIALS, Issue 19 2009Funct. Xing-Hua Li et al. describe the preparation of ionic liquid-doped polyaniline (IL-PANI) inverse opaline film with surface assemblies of gold nanoparticles. The resulting AuNP/IL-PANI film is conjugated with Hepatitis B surface antibody molecules to fabricate a immunosensor with a low detection limit for Hepatitis B surface antigen. [source] Ionic-Liquid-Doped Polyaniline Inverse Opals: Preparation, Characterization, and Application for the Electrochemical Impedance Immunoassay of Hepatitis B Surface AntigenADVANCED FUNCTIONAL MATERIALS, Issue 19 2009Xing-Hua Li Abstract A 3D ordered macroporous (3DOM) ionic-liquid-doped polyaniline (IL-PANI) inverse opaline film is fabricated with an electropolymerization method and gold nanoparticles (AuNPs) are assembled on the film by electrostatic adsorption, which offers a promising basis for biomolecular immobilization due to its satisfactory chemical stability, good electronic conductivity, and excellent biocompatibility. The AuNP/IL-PANI inverse opaline film could be used to fabricate an electrochemical impedance spectroscopy (EIS) immunosensor for the determination of Hepatitis B surface antigen (HBsAg). The concentration of HBsAg is measured using the EIS technique by monitoring the corresponding specific binding between HBsAg and HBsAb (surface antibody). The increased electron transfer resistance (Ret) values are proportional to the logarithmic value of the concentration of HBsAg. This novel immunoassay displays a linear response range between 0.032,pg mL,1 and 31.6,pg mL,1 with a detection limit of 0.001,pg mL,1. The detection of HBsAg levels in several sera showed satisfactory agreement with those using a commercial turbidimetric method. [source] Prevalence of hepatitis B and C: A Jinnah Postgraduate Medical Centre experienceJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2009Shehla Sami Abstract Aim:, To determine the prevalence of carriers of hepatitis B and C viruses among the obstetrical and gynecological population, the incidence of vertical transmission in obstetrical patients and to ascertain the risk factors associated with their transmission. Methods:, We conducted a prospective study over a 1-year period, from 1 January to 31 December 2005, comprising of an obstetrical population of 5902 deliveries and 548 major gynecology surgery patients. The study population was recruited by simple convenient sampling at Unit-I, Department of Obstetrics and Gynecology, Jinnah Postgraduate Medical Centre, Karachi, Pakistan. Booked obstetrical and major gynecological surgical patients were routinely screened by Enzyme Immunoassay for hepatitis B surface antigen (HbsAg) and anti-hepatitis C antibodies (anti-HCV) on venous blood samples. Liver function and carrier profile tests were performed on mothers who were positive for HBsAg. Babies of mothers with HbsAg were tested at birth for both HbsAg and HbeAg. Results:, Hepatitis B was detected in 275 pregnant women (4.6%) and in 70 (12%) gynecological patients. Hepatitis C was detected in 108 (1.8%) pregnant women and in 89 (16%) gynecological patients. Babies born to mothers with HBV or HCV infections tested negative. Four gynecological patients tested positive for both HBV and HCV infections. Unsafe surgery, injections and inadequately screened blood transfusions were the main underlying causes of infection. Conclusion:, Routine screening of the obstetrical population detected more cases of HBV infection than HCV, whereas HCV was more prevalent in the gynecological population, emphasizing the need for safe medical practices and patient education. [source] BIOCHEMICAL MARKERS OF CARDIAC INJURY IN NORMAL AND SURVIVING VERSUS NON-SURVIVING SEPTICEMIC NEONATAL FOALSJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue S1 2004SF Peek Although myocardial injury can be a significant component of multiple organ dysfunction (MODS) in association with septicemia in critically ill human patients, it is as yet an undefined clinical entity in equine septicemia. With septicemia as the leading cause of death in neonatal foals, a better understanding of the pathophysiology, diagnosis and treatment of MODS will be important in further improving survival rates. We designed a prospective study to establish normal ranges for cardiac troponin I (cTnI), T (cTnT) and CKMB mass in healthy 24,48 hour old foals, as well as septicemic neonatal foals seen over a 2-year period in a teaching hospital. We also performed a comparison of these biomarkers in surviving and non-surviving septicemic foals. Sepsis was judged on the basis of the presence of any of the 3 following criteria: blood culture positive at admission, admission sepsis score ,11, or 3 or more sites of infection during hospitalization in foals ,14 days of age. cTnI was measured by the ACCESS® (Beckman Coulter), cTnT was measured using the Elecsys 2010® Immunoassay (Roche), and CKMB mass measurements were performed using the Elecsys 2010®. Each parameter was described using range and 95th and 50th percentile. Comparisons were made for each parameter between normal and septic foals as well as surviving and non-surviving septic foals using the non-parametric Wilcoxon's rank sum test. Significance was set at p<0.05. There were 52 control foals and 38 septic foals of which 22 survived. Significant differences were documented for CKMB between septicemic and normal foals, but not for cTnT or cTnI. However, CKMB and cTnT were significantly lower in surviving versus non-surviving septicemic foals. The 50th and 95th percentiles alongside the ranges for the normal foal population were 0.14, 0.49, (0.01,0.51) ,g/L for cTnI, 0.009, 0.03, (0.009,0.04) ,g/L for cTnT and 2.3, 7.4, (0.4,9.3) ,g/L for CKMB. Our findings suggest that myocardial injury is a component of MODS during septicemia in foals, and that quantitatively significant increases in CKMB and cTnT are seen in non-surviving septicemic foals versus survivors. [source] Concentration of vascular endothelial growth factor (VEGF) in the serum of patients with malignant bone tumors,PEDIATRIC BLOOD & CANCER, Issue 6 2001Gerold Holzer MD Abstract Background Vascular endothelial growth factor (VEGF) is recognized as an important stimulator of angiogenesis. Formation of new blood vessels by angiogenic factors occurs in many biological processes, both physiological and pathological, among others in growth of primary solid malignant tumors and metastasis. This implies that the inhibition of angiogenic factors like VEGF would result in a suppression of tumor growth and metastasis formation. The aim of the present study was to compare preoperative serum VEGF levels of patients having malignant bone tumors with healthy controls to identify serum VEGF levels as a tumor marker. Procedure Blood sera from patients with high-grade osteosarcoma (n,=,17), chondrosarcoma (n,=,4) and Ewing sarcoma (n,=,6) were taken at the time of diagnosis before biopsy and compared with sera from 129 healthy persons. To measure VEGF levels in serum, a commercially available ELISA was used (Quantikine Human VEGF Immunoassay; R&D Systems). Results The observed geometric mean VEGF levels and 95% confidence intervals are 232.0 pg ml,1 (168.9,318.5) for patients with high-grade osteosarcoma, 325.5 pg ml,1 (169.3,625.8) for patients with chondrosarcoma, 484.3 pg ml,1 (284.0,826.0) for patients with Ewing sarcoma, as compared to 216.2 pg ml,1 (192.8,242.5) for healthy individuals. Conclusions While the sample means for the three groups of sarcoma patients were higher than the respective mean for the healthy controls, only the mean for the group with Ewing sarcoma is statistically significantly higher than the mean for the healthy controls. Despite the significant difference, VEGF levels are not suitable as a marker for Ewing sarcoma. Med. Pediatr. Oncol. 36:601,604, 2001. © 2001 Wiley-Liss, Inc. [source] Optimization of DNA Extraction from a Scleractinian Coral for the Detection of Thymine Dimers by Immunoassay,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007Anastazia T. Banaszak ABSTRACT Ultraviolet (UV)-B is known to cause DNA damage, principally by the formation of thymine dimers, but little research has been conducted in coral reef environments where UV doses are high. The majority of tropical reef-dwelling corals form a mutualistic symbiosis with the dinoflagellate Symbiodinium but few studies have been conducted on in situ DNA damage in corals and none have investigated the symbiotic components separately. The aim of this research was to quantify DNA damage in both the coral host and the dinoflagellate symbiont. The first step in this investigation was to optimize the extraction of DNA from the host, Porites astreoides, as well as the symbiont. The optimization was divided into a series of steps: the preservation of the samples, separation of the coral tissue from the skeleton, separation of the host tissue from the algal cells to prevent cross contamination as well as the extraction and purification of genomic DNA from the algae that are located intracellularly within the invertebrate animal tissue. The best preservation method was freezing at low temperatures without ethanol. After scraping with a razor blade, the coral tissue can be divided into host and algal components and the DNA extracted using modifications of published techniques yielding DNA suitable for the quantification of thymine dimer formation using antibodies. Preliminary data suggest that in P. astreoides collected from 1 m depth, thymine dimers form approximately 2.8 times more frequently in the host DNA than in the DNA of its symbionts. [source] Donor Screening for Human T-cell Lymphotrophic Virus 1/2: Changing Paradigms for Changing Testing CapacityAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010D. R. Kaul Organ Procurement and Transplant Network (OPTN) policy currently requires the testing of all potential organ donors for human T-cell lymphotrophic virus (HTLV)-1/2. Most Organ Procurement Organizations (OPO) use the Abbott HTLV-I/HTLV-II Enzyme Immunoassay (EIA). This assay will no longer be manufactured after December 31, 2009; the only commercially available FDA-licensed assay will be the Abbott PRISM HTLV-I/II assay which poses many challenges to OPO use for organ donor screening. As a result, screening donors for HTLV-1/2 in a timely manner pretransplant after December 31, 2009 will be challenging. The true incidence of HTLV-1 in United States (U.S.) organ donors is not well described but appears to be low (,0.03,0.5%). HTLV-1 is associated with malignancy and neurological disease; HTLV-2 has not been convincingly associated with disease in humans. Donors that are HTLV-1/2 seropositive are infrequently used despite most results being either false positive or resulting from HTLV-2 infection. There is urgent need to encourage the development of assays, instruments and platforms optimized for organ donors that can be used to screen for transmissible disease in donors; these must have appropriate sensitivity and specificity to identify all infections while minimizing organ loss through false positive testing. [source] Phospholipid-Coated Carbon Nanotubes as Sensitive Electrochemical Labels with Controlled-Assembly-Mediated Signal Transduction for Magnetic Separation Immunoassay,ANGEWANDTE CHEMIE, Issue 52 2009Huagui Nie Dr. Ein elektrochemisches Immunassay nutzt mehrwandige Kohlenstoffnanoröhren (MWNTs) mit Phospholipidüberzug als elektrochemische Markierungen (siehe Schema; PSA=Antigenprotein; MB=magnetisches Kügelchen). Die Signalübertragung bei dieser Strategie ist hoch empfindlich und spezifisch. [source] Competitive Enzymatic Fluorescence Immunoassay for Human IgG by Using a Temperature-Sensitive Phase Separating Polymer with Regulated Phase Transition TemperatureCHINESE JOURNAL OF CHEMISTRY, Issue 4 2008Peng LIN Abstract A new enzymatic fluorescence immunoassay for human IgG was developed using a temperature-sensitive polymer, poly(N -isopropylacrylamide-co-acrylamide) [P(NIP-AA)], as a carrier. The lower critical solution temperature of the P(NIP-AA) containing molar fraction of 8% for AA was 37 °C. In a competitive immunoassay, immobilized IgG and the standard IgG (or sample) competed for binding to a horseradish peroxidase labeled antibody at 33 °C in homogeneous format. After changing the temperature to separate the polymer-immune complex, the complex precipitate was re-dissolved and determined by coupling with the fluorescence reaction of hydrogen peroxide and p -hydroxyphenylacetic acid. The calibration graph for human IgG was linear over the range of 100,1000 ng/mL with a detection limit of 2.0 ng/mL. The method is rapid, sensitive and simple. The immune reaction efficiency was improved. In addition, the sensitivity of this method was close to that using traditional microtitration plates as carriers. However, the assay was much faster (the assay time decreased from 100,120 to 30 min). The method has been applied to the determination of the human IgG levels in human sera with satisfactory results. [source] Combination of B-Type Natriuretic Peptide Levels and Non-Invasive Hemodynamic Parameters in Diagnosing Congestive Heart Failure in the Emergency DepartmentCONGESTIVE HEART FAILURE, Issue 4 2004Erin Barcarse BS This study aimed to assess whether the combination of a B-type natriuretic peptide (BNP) level with various noninvasive hemodynamic parameters can help physicians more quickly and accurately diagnose congestive heart failure and determine the type of left ventricular dysfunction present in patients presenting to the emergency department with dyspnea. Subjects were 98 men (aged 64.57±1.23 years) that presented to the VA San Diego Healthcare System. Hemodynamic parameters were measured using impedance cardiography, and BNP levels were quantified using a rapid immunoassay. All patients with a BNP <100 pg/mL (n=37) had no evidence of congestive heart failure 97% of the time. In those with a BNP >100 pg/mL (601 ±55 pg/mL; n=61), a cardiac index of 2.6 L/min/m2 is 65% sensitive and 88% specific in determining systolic dysfunction. In patients with a BNP >100 pg/mL, a multivariate model consisting of noninvasive hemodynamic measurements was able to predict cardiac deaths, readmissions, and emergency department visits within 90 days with 83% accuracy. The authors conclude that, in patients presenting to an emergency department with dyspnea, the addition of impedance cardiography measurements to BNP level measurements will more effectively diagnose congestive heart failure and determine both the type of heart dysfunction and the severity of illness. [source] Proof of principle: An HIV p24 microsphere immunoassay with potential application to HIV clinical diagnosis,CYTOMETRY, Issue 3 2009Pascale Ondoa Abstract The measurement of CD4 counts and viral loads on a single instrument such as an affordable flow cytometer could considerably reduce the cost related to the follow-up of antiretroviral therapy in resource-poor settings. The aim of this study was to assess whether the HIV-1 p24 antigen could be measured using a microsphere-based flow cytometric (FC) assay and the experimental conditions necessary for processing plasma samples. A commercial anti-p24 antibody pair from Biomaric was used to develop a p24 microsphere immunoassay (MIA) using HIV culture supernatant as the source of antigen. The ultrasensitive Perkin Elmer enzyme immunoassay (EIA) served as a reference assay. Quantification of HIV p24 using the heat-mediated immune complex disruption format described for plasma samples was feasible using the Biomaric MIA and applicable to a broad range of HIV-1 Group M subtypes. The inclusion of a tyramide amplification step was successful and increased the fluorescence signal up to 3 logs as compared with the MIA without amplification. The analytical sensitivity of this ultrasensitive Biomaric assay reached 1 pg/mL, whereas the ultrasensitive Perkin Elmer EIA was sensitive to less than 0.17 pg/mL. Our data indicate, for the first time, that the principle of p24 detection using the heat-denatured ultrasensitive format can be applied to FC. © 2008 Clinical Cytometry Society [source] Cerebrospinal fluid insulin-like growth factors IGF-1 and IGF-2 in infantile autismDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 9 2006Raili Riikonen MD PhD There has been little exploration of major biologic regulators of cerebral development in autism. We measured insulin-like growth factors (IGF) -1 and -2 from cerebrospinal fluid (CSF) by radio immunoassay in 25 children with autism (median age 5y 5mo; range 1y 11mo-15y 10mo; 20 males, 5 females), and in 16 age-matched comparison children without disability (median age 7y 4mo; range 1y 1mo-15y 2mo; eight males, eight females). IGF-1 and -2 concentrations were further correlated with age of patients and head size. CSF IGF-1 concentration was significantly lower in patients with autism than in the comparison group. The CSF concentrations of children with autism under 5 years of age were significantly lower than their age-matched comparisons. The head circumferences correlated with CSF IGF-1 in children with autism but no such correlation was found in the comparison group. There was no difference between the two groups in CSF IGF-2 concentrations. No patients with autism had macrocephaly. We conclude that low concentrations of CSF IGF-1 at an early age might be linked with the pathogenesis in autism because IGF-1 is important for the survival of Purkinje cells of the cerebellum. The head growth might be explained by the actions of IGF-1 and -2 reflected in CSF concentrations. [source] Pigment-dispersing factor in the locust abdominal ganglia may have roles as circulating neurohormone and central neuromodulatorDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2001Magnus G. S. Persson Abstract Pigment-dispersing factor (PDF) is a neuropeptide that has been indicated as a likely output signal from the circadian clock neurons in the brain of Drosophila. In addition to these brain neurons, there are PDF-immunoreactive (PDFI) neurons in the abdominal ganglia of Drosophila and other insects; the function of these neurons is not known. We have analyzed PDFI neurons in the abdominal ganglia of the locust Locusta migratoria. These PDFI neurons can first be detected at about 45% embryonic development and have an adult appearance at about 80%. In each of the abdominal ganglia (A3,A7) there is one pair of lateral PDFI neurons and in each of the A5,A7 ganglia there is additionally a pair of median neurons. The lateral neurons supply varicose branches to neurohemal areas of the lateral heart nerves and perisympathetic organs, whereas the median cells form processes in the terminal abdominal ganglion and supply terminals on the hindgut. Because PDF does not influence hindgut contractility, it is possible that also these median neurons release PDF into the circulation. Release from one or both the PDFI neuron types was confirmed by measurements of PDF-immunoreactivity in hemolymph by enzyme immunoassay. PDF applied to the terminal abdominal ganglion triggers firing of action potentials in motoneurons with axons in the genital nerves of males and the 8th ventral nerve of females. Because this action is blocked in calcium-free saline, it is likely that PDF acts via interneurons. Thus, PDF seems to have a modulatory role in central neuronal circuits of the terminal abdominal ganglion that control muscles of genital organs. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 19,41, 2001 [source] Ultrasensitive Eletrogenerated Chemiluminescence Immunoassay by Magnetic Nanobead AmplificationELECTROANALYSIS, Issue 3 2010Mingyue Li Abstract An ultrasensitive electrogenerated chemiluminescence (ECL) immunoassay was proposed by using magnetic nanobeads (MNBs) as the carrier of ECL labels for ECL emission amplification. Carcinoembryonic antigen (CEA) and MNBs were initially immobilized on a platform in 1,:,1 molar ratio via sandwich immunoreaction. Subsequently, the MNBs were released from the platform and labeled with Ru(bpy)32+ species. After the MNBs with Ru(bpy)32+ were immobilized on an Au electrode, ECL of the Ru(bpy)32+ was measured for CEA determination. A linear relation between the ECL intensity and CEA concentration was obtained in a range of 1×10,14 to 3×10,13,mol/L (2.0 to 60,pg/mL) with a limit of detection of 8.0×10,15,mol/L (1.6,pg/mL). [source] Electrochemical Immunoassay for Carbohydrate Antigen-125 Based on Polythionine and Gold Hollow Microspheres Modified Glassy Carbon ElectrodesELECTROANALYSIS, Issue 17 2007Xiao-Hong Fu Abstract A new electrochemical immunosensor for the detection of carbohydrate antigen-125 (CA125), a carcinoma antigen, was developed by immobilization CA125 antibody (anti-CA125) on gold hollow microspheres and porous polythionine (PTH) modified glassy carbon electrodes (GCE). The gold hollow microspheres provided a biocompatible microenvironment for proteins, and greatly amplified the coverage of anti-CA125 molecules on the electrode surface. The performance and factors influencing the immunosensor were investigated in detail. The detection is based on the current change before and after the antigen-antibody interaction. Under optimal conditions, the amperometric changes were proportional to CA125 concentration ranging from 4.5 to 36.5,U/mL with a detection limit of 1.3,U/mL (at 3,). The CA125 immunosensor exhibited good precision, high sensitivity, acceptable stability, accuracy and reproducibility. The as-prepared immunosensors were used to analyze CA125 in human serum specimens. Analytical results suggest that the developed immunoassay has a promising alternative approach for detecting CA125 in the clinical diagnosis. [source] MCE enzyme immunoassay for carcinoembryonic antigen and alpha-fetoprotein using electrochemical detectionELECTROPHORESIS, Issue 19 2009Shusheng Zhang Abstract An MCE electrochemical enzyme immunoassay protocol for the determination of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was reported. Two antigens (Ag), CEA and AFP, were incubated simultaneously with an excess amount of horseradish peroxidase-labeled antibody (Ab*). The free Ab* and the Ab*,Ag complex produced in the solution were first separated through a postcolumn reaction and then traced by the enzyme substrate o -aminophenol. The 3-aminophenoxazine produced in enzyme reaction was detected with downstream amperometric detection. The separations were performed at a separation voltage of +1.4,kV and were completed in less than 60,s. The better analytical performance and distinct miniaturization/portability for MCE at less assay time and sample volume consumption was achieved. The detection limit of CEA and AFP was calculated to be 0.25 and 0.13,ng/mL, respectively. Therefore, MCE could be used as a sensitive and new tool in separation science and offered considerable promise in biological sample analysis or quick clinical diagnosis. [source] Cover Picture: Electrophoresis 14'09ELECTROPHORESIS, Issue 14 2009Article first published online: 28 JUL 200 Issue no. 14 is an Emphasis Issue with 9 articles on various aspects of "Proteins and Proteomics" while the remaining 14 articles are arranged into 4 different parts including "Microfluidics and Miniaturization", "Genotyping and Transcriptomics", "Enantioseparations", and "Nanoparticles and Abused Drugs Analyses". Selected articles are: Effective elimination of nucleic acids from bacterial protein samples for optimized blue native polyacrylamide gel electrophoresis ((10.1002/elps.200900026)) 2-D difference in gel electrophoresis combined with Pro-Q Diamond staining: A successful approach for the identification of kinase/phosphatase targets ((10.1002/elps.200800780)) Microvalves actuated sandwich immunoassay on an integrated microfluidic system ((10.1002/elps.200800818)) Chemical gradient-mediated melting curve analysis for genotyping of SNPs ((10.1002/elps.200800729)) [source] Cover Picture: Electrophoresis 4'09ELECTROPHORESIS, Issue 4 2009Article first published online: 26 FEB 200 Issue no. 4 is a special issue on "CEC and EKC" containing 20 papers including 2 Fast Track papers. The first Fast Track paper deals with high-resolution computer simulations of EKC while the second Fast Track paper reports the use of camera cell phone to detect the gold nanoparticle-labeled immunoassay results on microfluidic chip. The remaining 18 papers of this special issue are distributed into four parts. Part I is on monolithic capillaries for CEC and has five papers demonstrating the continuous efforts in developing novel monolithic stationary phases. Part II, which assembles six contributions, is on various aspects of MEKC separations of a wide range of compounds in the presence of different types of micelles. On-line concentration cum EKC/CEC is the subject of Part III that has five contributions demonstrating signal enhancement for various small and large molecules. This issue concludes with Part IV on enantioseparations by chiral EKC and CEC. [source] Competitive immunoassay by capillary electrophoresis with laser-induced fluorescence for the trace detection of chloramphenicol in animal-derived foodsELECTROPHORESIS, Issue 16 2008Can Zhang Abstract A competitive immunoassay using CE with an LIF detector was developed for the detection of chloramphenicol (CAP). The method was based on the competitive reactions between fluorescently labeled CAP hapten and free CAP, with a limited amount of anti-CAP antibody. The poly(N -isopropylacrylamide) (pNIPA) hydrogel was added in the separation buffer as a dynamic modifier to reduce adsorption and enhance reproducibility. The linear range and LOD for CAP were 0.008,5,,g/L and 0.0016,,g/L, respectively. An ELISA using the same immuno-reagents was also developed for the analysis of CAP, with an LOD of 0.03,,g/L. The sensitivity of this CE immunoassay (CEIA)-LIF was almost 20 times greater than that of the ELISA. Using CEIA-LIF, equilibrium was reached in 15,min and the analytical results were obtained within 5,min by CE separation. Sample preparation for CEIA-LIF was not time-consuming and the matrix effect was easy to remove. An LOD of 0.1,,g/kg CAP in food matrices was easily achieved. This method is thus proposed as a fast and sensitive means of detecting trace amounts of CAP residues in animal-derived foods. [source] Cover Picture: Electrophoresis 7/2008ELECTROPHORESIS, Issue 7 2008Article first published online: 2 APR 200 Regular issues provide a wide range of research and review articles covering all aspects of electrophoresis. Here you will find cutting-edge articles on methods and theory, instrumentation, nucleic acids, CE and CEC, miniaturization and microfluidics, proteomics and two-dimensional electrophoresis. Issue 7 also offers one Fast Track article describing particularly important investigations in electrophoresis: "Electrokinetic Analyte Transport Assay" for alpha - phetoprotein immunoassay integrates mixing, reaction and separation on-chip Tomohisa Kawabata, Henry G. Wada, Mitsuo Watanabe, Shinji Satomura [source] CE-based noncompetitive immunoassay for immunoglobulin G in bovine colostrum productsELECTROPHORESIS, Issue 21 2007Jin Zhao Abstract A CE-based noncompetitive immunoassay for IgG in bovine colostrum products was established. FITC-labeled protein G (FITC-PrG) was tagged through noncovalent bindings to the Fc region of the mouse monoclonal antibovine IgG (Ab). The FITC-PrG, Ab, and IgG formed a sandwiched immunocomplex FITC-PrG-Ab-IgG under optimal incubation conditions. The immunocomplex was separated and analyzed by CZE with LIF detection in less than 2,min in an uncoated fused-silica capillary. Addition of PEG 20,000 (PEG 20M) in the running buffer significantly suppressed analyte adsorption and thus improved the reproducibility and the resolution. The precision of the method was 5.1% (n,=,7). A linear relationship was established for the IgG concentration in the range of 1,5,mg/L with a linear correlation coefficient (r,=,0.9917). The LOD was 0.1,mg/L (S/N,=,3). The method was successfully applied for the determination of IgG in bovine colostrum products and satisfactory results were achieved. [source] Construction of an antibody microarray based on agarose-coated slidesELECTROPHORESIS, Issue 3 2007Lin-Li Lv Abstract The antibody microarray, a high-throughput multiplex immunoassay method, has become a significant tool for quantitative proteomics studies. We describe here the strategies for optimizing the condition of antibody microarray building based on agarose-coated slides. In this study, modified glass slides were robotically printed with capture antibodies against monocyte chemoattractant protein 1 (MCP-1), then dilutions of the cytokine were applied to the arrays, and the protein was detected with biotin-labeled antibody coupled with Cy3-conjugated streptavidin. Thus a protein profiling microarray based on sandwich immunoassay has been established. Various factors in the production of antibody microarrays were analyzed: the capture antibody concentrations, shelf life of the postprinting slides, blocking buffers, and reproducibility of the system. A calibration curve with a correlation coefficient of 0.9995 was established which suggested that the matrix can retain arrayed proteins in near-quantitative fashion. The results revealed high signal uniformity and reproducibility with regard to intra-array (1.3%) and the interarray (8.7%) variation at the capture antibody concentration of 125,µg/mL. Besides, the printed arrays could be stored for at least two months without any apparent change of the performance parameters. [source] Laser-induced fluorescence detection schemes for the analysis of proteins and peptides using capillary electrophoresisELECTROPHORESIS, Issue 13 2005Marlene Lacroix Abstract Over the past few years, a large number of studies have been prepared that describe the analysis of peptides and proteins using capillary electrophoresis (CE) and laser-induced fluorescence (LIF). These studies have focused on two general goals: (i) development of automatic, selective and quick separation and detection of mixtures of peptides or proteins; (ii) generation of new methods of quantitation for very low concentrations (nm and subnanomolar) of peptides. These two goals are attained with the use of covalent labelling reactions using a variety of dyes that can be readily excited by the radiation from a commonly available laser or via the use of noncovalent labelling (immunoassay using a labelled antibody or antigen or noncovalent dye interactions). In this review article, we summarize the works which were performed for protein and peptide analysis via CE-LIF. [source] Seasonal succession of Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum blooms with cylindrospermopsin occurrence in the volcanic Lake Albano, Central ItalyENVIRONMENTAL TOXICOLOGY, Issue 1 2010Valentina Messineo Abstract The cyanobacterial toxin cylindrospermopsin is rapidly spreading in the European temperate Countries. Cylindrospermopsin was detected for the first time in Italy in 2004; in this study, the presence of this toxin in Albano Lake (Central Italy) has been correlated to the cyanobacterial species Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum and their population dynamics. In 2004, these two species succeeded in the lake during spring, summer, and early autumn without overlapping, causing superficial blooms. Cylindrospermopsin was detected in lake samples by LC-MS/MS and ELISA immunoassay, showing extracellular superficial values ranging from 2.6 to 126 ,g/L, and water column values ranging from 0.41 to 18.4 ,g/L. Twenty-six of 30 positive water samples (86%) exceeded the recommended limit of 1 ,g/L. Intracellular values up to 42.3 ,g/g were measured. Moreover, cylindrospermopsin was detected in tissues from two Salmo trutta trouts (up to 2.7 ng/g) and in a well for drinking water supply (1.6 ,g/L). For the first time, two cyanobacterial species producing cylindrospermopsin were detected in the same lake in Italy. © 2009 Wiley Periodicals, Inc. Environ Toxicol 2010. [source] Microcystin-LR modulates selected immune parameters and induces necrosis/apoptosis of carp leucocytes,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2010Anna Rymuszka Abstract Microcystins (MCs) are potent hepatotoxins acting by the inhibition of protein phosphatase 1 and 2A, and may promote liver tumors. Moreover, studies also suggest they are nephrotoxic. The aim of the present study was to assess possible in vitro effects of microcystin-LR (which contains the amino acids leucine and arginine, the most widely studied and distributed variant of all microcystins) on the selected immune functions of the cells isolated from the head kidney of carp. In the experiments, pure microcystin-LR (MC-LR), was used at concentrations of 0.01, 0.1, 0.5, and 1,µg/ml RPMI-1640 medium. Leucocytes (lymphocytes and phagocytes) were isolated by centrifugation on a density gradient. Lymphocyte proliferation, intracellular production of reactive oxygen species by phagocytes, and the presence of apoptotic and/or necrotic cells were assessed. The respiratory burst activity of phagocytic cells was increased at the lowest toxin concentration used in the study, but it was decreased at higher concentrations. Using a sensitive luminescent immunoassay, MC-LR was observed to have no influence on the T-cell proliferation but decreased the proliferation of B lymphocytes. Moreover, it was noted that MC-LR induced necrosis to a higher degree than apoptosis in fish leucocytes. The results of the present study suggest the modulatory potency of microcystin-LR on fish leucocytes. Environ. Toxicol. Chem. 2010;29:569,574. © 2009 SETAC [source] A new rapid micromethod for the assay of phenobarbital from dried blood spots by LC-tandem mass spectrometryEPILEPSIA, Issue 12 2009Giancarlo La Marca Summary Advantages of dried blood spot include low invasiveness, ease and low cost of sample collection, transport, and storage. We used tandem mass spectrometry (LC-MS/MS) to determine phenobarbital levels on dried blood spot specimens and compared this methodology to commercially available particle enhanced turbidimetric inhibition immunoassay (PETINIA) in plasma/serum samples. The calibration curve in matrix using D5 -phenobarbital as internal standard was linear in the phenobarbital concentration range of 1,100 mg/L (correlation coefficient 0.9996). The coefficients of variation in blood spots ranged 2.29,6.71% and the accuracy ranged 96.54,103.87%. There were no significant differences between the concentrations measured using PETINA and LC-MS/MS (both had similar precision and accuracy) however, LC-MS/MS allows at least 1.5 times higher throughput of phenobarbital analysis and additionally offers ease of sample collection which is particularly important for newborns or small infants. [source] Carbamylated erythropoietin increases frataxin independent from the erythropoietin receptorEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2010Brigitte Sturm Eur J Clin Invest 2010; 40 (6): 561,565 Abstract Background, Friedreich's ataxia (FRDA) is a neurodegenerative disorder caused by decreased expression of the mitochondrial protein frataxin. Recently we showed in a clinical pilot study in Friedreich's ataxia patients that recombinant human erythropoietin (rhuEPO) significantly increases frataxin-expression. In this in vitro study, we investigated the role of the erythropoietin receptor (EPO-R) in the frataxin increasing effect of rhuEPO and if nonerythropoietic carbamylated erythropoietin (CEPO), which cannot bind to the classical EPO-R increases frataxin expression. Materials and methods, In our experiments human erythroleukaemic K562 cells (+ EPO-R), human monocytic leukemia THP-1 cells (, EPO-R) and isolated primary lymphocytes from healthy control and FRDA patients were incubated with different concentrations of rhuEPO or CEPO. Frataxin-expression was detected by an electrochemical luminescence immunoassay (based on the principle of an ELISA). Results, We show that rhuEPO increases frataxin-expression in K562 cells (expressing EPO-R) as well as in THP-1 cells (without EPO-R expression). These results were confirmed by the finding that CEPO, which cannot bind to the classical EPO-R increased frataxin expression in the same concentration range as rhuEPO. In addition, we show that both EPO derivatives significantly increase frataxin-expression in vitro in control and Friedreich's ataxia patients primary lymphocytes. Conclusion, Our results provide a scientific basis for further studies examining the effectiveness of nonerythropoietic derivatives of erythropoietin for the treatment of Friedreich's ataxia patients. [source] Circulating levels of copeptin, a novel biomarker, in lower respiratory tract infectionsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2007B. Müller Abstract Background, Vasopressin has haemodynamic as well as osmoregulatory effects, and reflects the individual stress response. Copeptin is cosynthesized with vasopressin, directly mirroring vasopressin levels, but is more stable in plasma and serum. Both levels are increased in patients with septic shock. Lower respiratory tract infections (LRTI) are a precursor of sepsis. Thus, we investigated circulating levels and the prognostic use of copeptin for the severity and outcome in patients with LRTI. Materials and methods, Five hundred and forty-five consecutive patients with LRTI and 50 healthy controls were evaluated. Serum copeptin levels were measured with a new chemiluminescens sandwich immunoassay. Results, Of the 545 patients, 373 had community-acquired pneumonia (CAP), 60 acute exacerbations of chronic obstructive pulmonary disease (COPD), 59 acute bronchitis, 13 exacerbations of asthma and 40 other final diagnoses. Copeptin levels were significantly higher in patients with LRTI as compared to controls (P < 0·001) with highest levels in patients with CAP. Copeptin levels increased with increasing severity of CAP, as classified by the pneumonia severity index (PSI) (P < 0·001). In patients who died, copeptin levels on admission were significantly higher as compared to levels in survivors [70·0 (28·8,149·0) vs. 24·3 (10·8,43·8) pmol L,1, P < 0·001]. The area under the receiver operating curve (AUC) for survival was 0·75 for copeptin, which was significantly higher as compared to C-reactive protein (AUC 0·61, P = 0·01), leukocyte count (AUC 0·59, P = 0·01) and similar to procalcitonin (AUC 0·68, P = 0·21). Conclusions, Copeptin levels are increased with increasing severity of LRTI namely in patients with CAP and unfavourable outcome. Copeptin levels, as a novel biomarker, might be a useful tool in the risk stratification of patients with LRTI. [source] | |||||||||||||||||||||||||||||||||||||