Chicken Immunoglobulin G [Agarose]

In this paper, a rationally designed aptasensing platform based on Hybridization Chain Reaction (HCR) and G-quadruplex DNAzyme for the fluorescence detection of Carcinoembryonic Antigen (CEA) has been developed. In the presence of target CEA, the aptamer sequence in Aptamer Probe (AP) specifically bound to CEA, resulting in the AP conformation change and thus releasing initiator, which triggered the autonomous cross-opening of Hairpin 1 (H1) and Hairpin 2 (H2) that yielded extended nicked double-stranded DNA via HCR. Upon the addition of hemin, G-rich segments at the end of H1 and H2 self-assembled into the peroxidase-mimicking hemin/G-quadruplex DNAzymes, which catalyzed the hydrogen peroxide-mediated oxidation of thiamine to achieve fluorescence detection of CEA. The HCR product, and the formation and catalytic performance of DNAzyme were characterized by agarose gel electrophoresis, UV-vis spectroscopy and fluorescence spectroscopy, respectively. Under optimal conditions, the fluorescent aptasensor showed a linear relationship ranging from 0.25 to 1.5 nM toward CEA with a detection limit of 0.2 nM. In addition, this aptasensor exhibited high selectivity for CEA without being affected by other interfering proteins, such as IgG, AFP and PSA. Furthermore, this proposed aptasensor was successfully applied to CEA analysis in diluted human serum samples. It is believed that this strategy has a promising potential in biochemical analysis and clinic application.

Background: Herpes zoster (HZ) risk is high in renal transplant recipients. Vaccination prior to transplantation may provide a useful strategy for the prevention of HZ in the posttranplantation period. However, it is not known whether immunity to varicella-zoster virus (VZV) is affected due to treatment surrounding transplantation. Methods: Both humoral and cellular immunity to VZV were determined prior to and 2-3 years after renal transplantation in 60 adult patients, and 62 matched healthy controls. VZV-specific cellular immunity was measured by an interferon gamma (IFN gamma) enzyme-linked immunospot (ELISpot) assay and by analyzing T-cell functionality using flowcytometry. VZV-IgG levels were measured using an in-house glycoprotein enzyme-linked immunosorbent assay (gpELISA). Results: Using paired analysis, it was determined that numbers of IFN gamma-producing cells did not change after transplantation, but were significantly lower in transplant recipients after transplantation than in controls (p = 0.028). Patients in whom the post-transplant period was complicated by rejection or any acute infection (excluding HZ) had a lower number of IFN gamma-producing cells than patients who did not. VZV IgG levels did not differ from controls, but a significant decrease was observed after transplantation (p < 0.0001). Conclusions: VZV-specific cellular immunity, which is essential in the prevention of HZ, did not markedly change in patients following renal transplantation. This suggests that preventive vaccination before transplantation may be beneficial. Our results extend knowledge on VZV immunity after transplantation, vital when considering strategies for the prevention of HZ in these patients.