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Magnetic Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
In a different study (Kim et al. 2007), a slightly dissimilar scheme was implemented to detect the beta subunit of human chorionic gonadotrophin (HCG-β), a glycoprotein hormone composed of 244 amino acids with a molecular mass of 36.7 kDa, and a biomarker concerned with prostate and ovarian cancers. In this case, two different monoclonal antibodies that bind different, nonoverlapping epitopes (localized regions on the surface of an antigen that is capable of eliciting an immune response and of combining with a specific antibody to counter that response) on the HCG-β protein were attached to separate CLIO nanoparticle populations. Monoclonal antibodies are the highly specific antibodies, compared with polyclonal antibodies, which can be produced in large quantity by the clones of a single hybrid cell formed in the laboratory.
Biologic Drug Substance and Drug Product Manufacture
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Ajit S. Narang, Mary E. Krause, Shelly Pizarro, Joon Chong Yee
Structurally, Ig is commonly represented in a typical Y-arm structure (Figure 8.1) consisting of two large/heavy and two small/light polypeptide chains joined by disulfide bridges. Antibody fragments consist of a (mostly) constant region (designated, Fc) and an antigen-binding region (designated, Fab). Antibodies that recognize multiple sites of an antigen are termed polyclonal, whereas antibodies that target only a specific site are monoclonal. Identical immune cells make monoclonal antibodies, whereas polyclonal antibodies are produced by a mass of immune cells that may produce antibodies against different regions of the antigen. In industrial applications, monoclonal antibodies are prepared using recombinant DNA technology in cultured cells. For human clinical applications, monoclonal antibodies are generally preferred. Polyclonal antibodies are utilized for diagnostic and lab use such as immunohistochemistry.
Interference and Selectivity in Portable Chemical Sensors
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Antibodies are by far the most common affinity-based recognition elements. They are both highly sensitive and highly selective. Polyclonal antibodies are cheap but require animals to be immunized to obtain them and are vulnerable to nonspecific binding (interference from undesirable analytes). Monoclonal antibodies do not have these specificity problems but are costly and time consuming (Van Dorst et al., 2010). Used as chemical sensors in nonclinical applications, sensors based on the use of both polyclonal and monoclonal antibodies are highly vulnerable to losing their highly specific binding affinities under changing environmental conditions (Van Dorst et al., 2010). Thus, while antibodies have the potential for a variety of lock-and-key chemical interactions, their use as chemical sensors outside clinical applications is impractical.
Generation and evaluation of anti-mouse IgG IgY as secondary antibody
Published in Preparative Biochemistry & Biotechnology, 2020
Qi Zhang, Dongyang He, Long Xu, Shikun Ge, Jinquan Wang, Xiaoying Zhang
Polyclonal antibodies have always played an important role as secondary antibody in the basic and applied study of immunological analysis. In order to ensure the continuous growth of market demand, the production companies have massively increased the number of immunized animals and used hyper-immune strategies to improve the antibody titer. However, this is bound to produce strong animal welfare concerns.[15,16] IgY technology has significant advantages in terms of productivity, animal protection, and antibody specificity. In addition, due to structural differences and phylogenetic distance, IgY is more suitable for various diagnostic purposes than mammalian antibodies because it does not respond to certain components of the human immune system and has a higher affinity for mammalian conserved proteins.[17]
Mechanisms Associated with Protective Effects of Ginkgo Biloba Leaf Extracton in Rat Cerebral Ischemia Reperfusion Injury
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Wei Song, Jun Zhao, Xu-Sheng Yan, Xin Fang, Dong-Sheng Huo, He Wang, Jian-Xin Jia, Zhan-Jun Yang
For low, intermediate or high GbE doses and MCAO alone, the brain tissue around the infarct core area was separated. Similar brain area tissues were taken from control and sham group. The tissue was ground at low temperature with cell lysis solution, protease inhibitor, and ultrasonic dispersion. The homogenate was centrifuged for 30 min at 4°C at 12,000 g, and the supernatant obtained after 24 h. Protein concentrations were measured using a Bio-Rad protein assay kit (Bio-Rad, USA), and separated on 10% SDS-polyacrylamide gels, and transferred to polyvinylidenedifluoride (PVDF) membranes by electroblotting as described previously (Jia et al. 2016, 2018). The strips were cut according to molecular weight. The membranes were reacted with rabbit polyclonal antibodies for TNF-α and IL-6 12 h then incubated overnight with goat anti-rat secondary antibody at 37°C for 2 h. The intensities of the immunoreactive bands were quantified by Quantity One software (Bio-Rad, USA). On the second day, the chemical staining was performed. The positively stained cells were visualized by a microscope at ×100 magnification. Results were presented as mean ± SD in triplicate.
Involvement of apoptosis in the protective effects of Dracocephalum moldavaica in cerebral ischemia reperfusion rat model
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Peng Wu, Xu-Sheng Yan, Li-Li Zhou, Xin-Lang Liu, Dong-Sheng Huo, Wei Song, Xin Fang, He Wang, Zhan-Jun Yang, Jian-Xin Jia
Whole brain tissue sections were also used for immunohistochemical and Western blot analysis analyses as described by Ishii et al. (2012) and Huo et al. (2016). Briefly, the sections obtained were dewaxed and hydrated with 3% hydrogen peroxide, and then treated with antibodies (1:400) for 24 h. Protein concentrations were measured using a Bio-Rad protein assay kit (Bio-Rad, USA), and sodium dodecy1 sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of samples was performed with gels comprised of 8% acrylamide and 4% bisacrylamide. Proteins were transferred from gels to polyvinylidene fluoride (PVDF) membranes by electroblotting. The membranes were reacted with rabbit polyclonal antibodies for p53 (1:1000), bax (1:1000) and bcl-2 (1:1000) at 4°C for 12 h, respectively, then incubated with goat anti-rat secondary antibody at 37°C for 2 h. The intensities of the immunoreactive bands were quantified by Quantity One software (Bio-Rad, USA). On the second day the chemical staining was performed. The positively stained cells were visualized by a microscope at ×100 magnification. Results were presented as mean ± SD in triplicate.