Antibodies species reactivity

L/mole). It cross-reacts at >90% with saxitoxin but at <1% with neosaxitoxin. This antibody, when used in an anti-rabbit IgG "second antibody" radioimmunoassay format, can detect pmole quantities of saxitoxin. This assay has been shown to be a simple and efficient method for the analysis of saxitoxin in clam extracts. The lack of antibody cross-reactivity to the neosaxitoxin sub-group of the paralytic shellfish poisons limits the general utility of the assay to neurophysiology studies and to certain clam species which preferentially accumulate saxitoxin. However, the radioimmunoassay serves as a good precursor in the development of an enzyme immunoassay for the paralytic shellfish poisons. 

Cross-reactivity of antibodies to human antigens with identical or similar antigens of other species, or cross-species cross-reactivity, can be of interest to the researcher and veterinarian because of the scarcity of animal-specific antibodies. To overcome this, two publications reported the results of cross-species reactivity studies using commercially available antihuman polyclonal and monoclonal antibodies (10, 11). It was demonstrated that the majority of animal... 

For most of the other monoclonal antibodies, species cross-reactivity has been limited to nonhuman primates. For these molecules the need to conduct reproductive and developmental studies has to be carefully considered on a case-by-case basis. S5A states that nonhuman primates are best used when the objective of the study is to characterize a relatively certain reproductive toxicant, rather than detect a hazard. The nonhuman primate reproductive toxicity studies are not powered to detect infrequent events. 

A secondary linking antibody solution reactive against the immunoglobulin of the species responsible for the other two reagents. 

Species reactivity - The species where the antibody binds the antigen. If the antibody does not react to the species of your tissue or has not been tested against the species you are using, do not use it. Some vendors will send a sample to test for a new species. Alternatively, the species that the antibody does not react with might also be listed. This is important because not all antibodies will bind equally to antigens from different species. 

False negative results for cTn may occur if the assay is insufficiently sensitive, especially in enzyme-linked immunosorbent assay (ELISA) methods where colorimetry rather than fluorescence or chemiluminescence is used as the detection method, and in those assays with poor cross-species reactivity. False negative results may also occur in samples that have deteriorated. Serum cTn is stable at -70°C, but it deteriorates several percent per day at 4°C and by 10% per week at -20°C. Rare false positive results may occur with circulating heterophilic antibodies, fibrin clots, or incomplete serum separation (or in the presence of rheumatoid factor). Hemolysis produces negligible interference. 

Before proceding, confirm that the two secondary antibodies to be used will not recognize each other. For example, do not use a combination of rat anti-mouse and goat anti-rat secondary antibodies. The problem of secondary antibody cross-reactivity can be avoided if secondary antibodies raised in a single species such as goat are used. 

It was established that Ab to Klebsiella pneumoniae didn t demonstrate the cross-reactivity to antigens of the relative bacterial species so, it could be considered that antibodies investigated was highly specific only to the own antigen. The physical-chemical characteristics of the immunological interaction such as constants of formation of Ag-Ab complex were obtained. The binding constants of immune complex were Ka =(9.7 l.l)-10 and Ka,=(1.7+0.3)T0 (mg/ml)f... 

Second, the reactive species of a xenobiotic may bind to a protein, altering its antigenicity. The xenobiotic is said to act as a hapten, ie, a small molecule that by itself does not stimulate antibody synthesis but will combine with antibody once formed. The resulting antibodies can then damage the cell by several immunologic mechanisms that grossly perturb normal cellular biochemical processes. 

Blount, S., Griffiths, H.R., Staines, N.A. and Lunec, J. (1992). Probing molecular changes induced in DNA by reactive oxygen species with monoclonal antibodies. Immunol. Lett. 34, 115-126. 

Lymphocytes, the effector cells of the acquired immune system, include morphologically indistinguishable T and B cells, the former divided into CD4+ T helper cells and CD8+ cytotoxic T cells. Since the functions of those cell subsets differ so drastically, it became important to develop tools to distinguish them from each other. Efforts to identify cell subsets according to their expression of different surface antigens have been successful, including various Cluster of Determination (CD) markers (Table 23.1). In addition, cross-reactive monoclonal antibodies, and subsequently developed species-specific polyclonal and monoclonal antibodies towards the major histocompatibility complex (MHC) have been used to label cells in circulation and in tissue sections (Table 23.1). 

Fig. 1. Transmission mechanisms. Strain barrier PrPc (circle) interacts with different strains of PrPSc (square or triangle). The replicated PrPSc is similar to the template. The 3F4 epitope is not recognized when it is in PrPSc, but is exposed after pardal denaturation by GdnHCI so that it is detected by the antibody. Antibody reactivity depends on the particular strain of PrP (Safar et aL, 1998). Species barrier when the template PrPSc contains unfavorable residues at the binding interface, the transformation of PrPc to Pr l>Sr does not occur. In vitro replication 35S label of PrPc is detected in PrPSc after replication in a medium containing GdnHCI (Kocisko et aL, 1994).

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