Polyclonal selection

Performing polyclonal selection (Section 8.4.1) as an alternative to the selection of clones. 

To date, the most extensively studied polyboron hydride compounds in BNCT research have been the icosahedral mercaptoborane derivatives Na2[B22H22SH] and Na [(B22H22S)2], which have been used in human trials with some, albeit limited, success. New generations of tumor-localizing boronated compounds are being developed. The dose-selectivity problem of BNCT has been approached using boron hydride compounds in combination with a variety of deUvery vehicles including boronated polyclonal and monoclonal antibodies, porphyrins, amino acids, nucleotides, carbohydrates, and hposomes. Boron neutron capture therapy has been the subject of recent reviews (254). 

A. nidulans with selected phages of classes A, B, C, D and E resulted in increased polygalacturonase activity in comparison with the wild type strain. The culture media of pga transformants were further analysed by Western blotting with polyclonal antibodies raised against PGI and in all samples examined cross-reactive bands with molecular masses similar to that found for PGI or PGII were detected. 

A wide selection of monoclonal and polyclonal anti-Ca -ATPase antibodies have become available in recent years. Studies with these antibodies defined the localization of Ca " -ATPase in the sarcoplasmic reticulum of developing and mature skeletal muscles [60,262-270] and established a pattern of cross reactivity with various Ca -ATPase isoenzymes in the sarco(endo)plasmic reticulum [270-286] and in the plasma membrane [284,287-290] of skeletal, cardiac and smooth muscles. Antibodies have also proved useful in the quantitation of Ca -ATPase, both in muscles of diverse fiber types [291-294] and in COS-1 cells transfected with Ca -ATPase cDNA [97,103,126,127,129,215],... 

TES-45 and TES-55 are two glycoproteins that have yet to be identified at a genetic level, but evidence has been obtained that they may also be lectins. Carbohydrate affinity chromatography with mannose-agarose shows that TES-32 selectively binds as expected, but that TES-45 is also present in small amounts (Loukas et al., 1999) unlike TES-32, TES-45 does not bind to A -ace Lylgalac t< isamine. No sequence information has yet been obtained on TES-45, but it is recognized by polyclonal antibodies generated to TES-32,... 

Carrier protein Macromolecule to which a hapten is conjugated, thereby enabling the hapten to stimulate the immune response. catELISA Similar to an ELISA, except that the assay detects catalysis as opposed to simple binding between hapten and antibody. The substrate for a reaction is bound to the surface of the microtitre plate, and putative catalytic antibodies are applied. Any product molecules formed are then detected by the addition of anti-product antibodies, usually in the form of a polyclonal mixture raised in rabbits. The ELISA is then completed in the usual way, with an anti-rabbit second antibody conjugated to an enzyme, and the formation of coloured product upon addition of the substrate for this enzyme. The intensity of this colour is then indicative of the amount of product formed, and thus catalytic antibodies are selected directly. 

Carefully selected monoclonal antibodies against apo(a) are well suited for most immunoassays (LI, L2, W17). Precipitation techniques such as nephelome-try or turbidimetry require monospecific polyclonal antisera. 

The binding of the antigen and antibody can be affected by several factors, including the conjugated label chosen for detection and the method used to conjugate the label, as well as the assay format itself. The selectivity of the ELISA can be affected by the assay format. In an ELISA with a two-site sandwich format, independent epitopes are bound by different antibodies.26 The specificity comes from multiple site recognition. Polyclonal antibodies can react with many epitopes on a complex antigen surface.24... 

In most examples in the literature, polyclonal antibodies are used for preparing such columns but the increasing availability of monoclonal antibodies (MAbs) should lead to affinity gels based on MAbs becoming available. Such specificity would be particularly valuable where peptide drugs have to be selectively extracted from biological matrices prior to analysis. 

Siemann, M., Syldatk, C. and Wagner, F. (1993) Detection and comparison of strains with selective L-hydantoin cleaving activity using polyclonal antibodies. Biotechnol. 

Although both polyclonal and monoclonal antibodies have been effectively used in immunochemical assays, only the latter can provide the high specificity required in some applications. Antibody specificity, on the other hand, is both a major advantage and disadvantage for immunochemical methods. It allows for highly selective detection of analytes but at the same time may complicate the development of multiresidue methods. Moreover, production of monoclonal antibodies requires special expertise and it is much more expensive than polyclonal antibodies. Thus, in cases where a range of analytes similar in molecular structure are required to be determined, a polyclonal may be more suitable than a monoclonal antibody. 

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