Establishment Of Enzyme-linked Immunosorbent Assay Research Articles

Establishment of enzyme-linked immunosorbent assay for beef and lamb contents in cooked meat

In this study, an enzyme-linked immunosorbent assay (ELISA) was established to detect beef and lamb components, and its performance was tested. Double-antibody sandwich ELISA was adopted and determined a coating concentration of capture antibody 3G5 of 1:4 000, a working concentration of enzyme-labeled antibody 2E7-horseradish peroxidase (HRP) of 1:1 000, a sample incubation time of 60 min and a detection antibody reaction time of 60 min. The specificity, sensitivity, repeatability and stability of this assay were determined. The limit of detection for beef and lamb skeletal muscle troponin I was 45 mg/kg, the inter-assay and intra-assay recovery rates ranged from 80.4% to 115.7%, the coefficients of variation were below 13.6%, and the cross reaction rates of the tissue components of chicken, duck and fish were below 13.4%. The sandwich ELISA method established in this study is stable and has high accuracy. The test results were consistent with the polymerase chain reaction (PCR) method at 50 and 100 g/kg. Therefore, this ELISA method can be used to quantitatively detect beef and lamb components in meat products.

Establishment of enzyme-linked immunosorbent assay in the detection of BP180NC16A-specific IgE and its significance in bullous pemphigoid

To establish a method of detecting circulating immunoglobulin E (IgE) autoantibodies for BP180NC16A and evaluate its significance in bullous pemphigoid (BP). GST-NC16A fusion proteins were expressed in Escherichia coli using the pGEX-2T expression system and purified by glutathione affinity chromatography.For optimal working conditions of enzyme-linked immunoabsorbent assay (ELISA), checkerboard titrations were performed with serial dilutions of antigen. Also optimized dilution of secondary antibody was confirmed. Sera samples from 56 patients with BP, 24 healthy controls, 18 with pemphigus and 1 with Stevens-Johnson syndrome at our hospital during February 2011 to October 2012 were examined by the modified ELISA approach. The optimal cut-off point for a positive result was selected with receiver operating characteristic analysis. The optimized ELISA was performed with plates coated with 500 µg/ml GST-NC16A. And the optimal dilutions of sera samples and secondary antibody were 1: 10 and 1: 1000 respectively. According to the established cut-off value (0.549), 40 of 56 BP patients and none of controls had detectable levels of BP180NC16A IgE. The established ELISA provides a highly specific tool for the detection of IgE anti-BP180NC16A in BP patients.

Non-HLA-antibodies targeting Angiotensin type 1 receptor and antibody mediated rejection

Antibody-mediated mechanisms directed against non-HLA related targets may exert negative impact on allograft function and survival. Angiotensin type 1 receptor (AT(1)R) emerges as a functional target for non-HLA allo- and autoantibodies (AT(1)R-Abs) comprising of IgG1 and IgG3 subclasses. Proof of concept for pathophysiologic relevance of AT(1)R-Abs in antibody mediated rejection (AMR) in renal transplants was provided by passive transfer studies in animal model and therapeutic rescue of patients. Although AT(1)R-Abs may belong to complement fixing IgG subclasses, C4d positivity in renal transplant biopsies was not frequently detected implicating complement independent mechanisms of injury. AT(1)R-Abs exert direct effects on endothelial and vascular smooth muscle cells by induction of Erk1/2 signaling and increased DNA binding of transcription factors associated with pro-inflammatory and pro-coagulatory responses. Establishment of enzyme-linked immunosorbent assay employing extracts of cells overexpressing AT(1)R in its native conformation was instrumental for recent studies in independent cohorts. Assessing the AT(1)R-Ab-status along with the HLA-antibodies may help to identify patients at particular risk for irreversible acute or chronic allograft injuries and improve overall outcomes. This review summarizes the current state of research in AT(1)R biology, development in diagnostic strategies, discusses recent clinical studies, and provides perspectives on further refinements in understanding AT(1)R-Ab-actions.

Establishment of enzyme-linked immunosorbent assay using purified recombinant 83-kilodalton antigen of Borrelia burgdorferi sensu stricto and Borrelia afzelii for serodiagnosis of Lyme disease

The 83-kDa antigen of Borrelia burgdorferi was expressed as a recombinant protein in Escherichia coli and purified for use in an enzyme-linked immunosorbent assay (p83-ELISA). Antibodies to the 83-kDa antigen of both the immunoglobulin G (IgG) and IgM isotypes could be detected in all stages of Lyme disease. Sensitivity varied, depending on the clinical stage of illness. In early stages, as defined for 118 patients with erythema migrans, it was found to be 20% (24 of 118 patients: 7 with IgM, 16 with IgG, and 1 with IgM and IgG). Of the patients with late-stage Lyme arthritis and acrodermatitis chronica atrophicans, 94% (16 of 17:2 with IgM and IgG and 14 with IgG) and 86% (36 of 42:2 with IgG and IgM and 34 with IgG) revealed positive results in the p83-ELISA, respectively. p83 displays sequence heterogeneity according to the genomospecies, but when the reactions of serum specimens from acrodermatitis chronica atrophicans patients and arthritis patients with p83 derived from representative strains of B. burgdorferi sensu stricto and Borrelia afzelii in ELISAs were compared, no differences in specificity and sensitivity were seen. When 82 serum specimens from healthy controls were tested, none had IgG and only 3 (4%) had IgM antibodies, indicating a high specificity. Positive reactions with antibodies against Treponema pallidum (1 of 37 patients; IgG) and Epstein-Barr virus (1 of 44 patients; IgM) and with autoantibodies of various specificities (1 of 53 patients; IgG) were seen with < 3% of the serum samples te11111111111111111111 high speficicity for B. burgdorferi.2+ 13% for IgM antibodies, the IgM p83-ELISA provided little diagnostic information for Lyme disease, whereas the IgG p83-ELISA appears to be a suita ;e test for serodiagnosis of advanced-stage Lyme disease.

アメーバ症の血清学的診断法に関する基礎的研究

We studied the establishment of enzyme-linked immunosorbent assay (ELISA) using amoebic antigen for complement fixation (CF) test. Optimal dilution for ELISA of sera from patients was 1:100, and that of CF-antigen was 1:400. The upper limit of the 99% critical range of the reaction of negative sera was 0.068 (cut-off level). Absorbance of sera from patients diluted 1:100 to antigen and antibody titers of ELISA were strongly correlated, so it was possible to estimate antibody titers from absorbance of serum diluted 1:100. ELISA and CF test were done to compare sensitivity of the tests using 63 sera from patients with invasive amoebic disease. The sensitivity of ELISA compared well with CF test (62 sera were positive by ELISA and 61 by CF test). Only one sample was both positive by ELISA and negative by CF test. This sample had low ELISA titers, so this discrepancy was mainly due to the sensitivity of CF test in detecting lower levels of antibody. These results suggested that the amoebic antigen for CF test can be applicable to ELISA, and this method was so sensitive and specific.