Creative Biolabs provides high-quality service in phage display antibody library construction and screening. In order to select antibodies with high affinity and specificity, we have developed a series of selection strategies. Antibody-guided selection strategy by using capture-sandwich ELISA can be strongly effective to select antibodies (Abs) specificity against antigens (Ags) from crude preparations.
The phage surface display technology has offered an efficient route to obtain a diverse set of monoclonal antibodies (mAbs) with the desired specificity. Although the mAbs selected by phage display technology have a wide range of applications, this technology is strongly expected to provide more powerful diagnostic, prophylactic, and therapeutic means of human origin than polyclonal Abs or mAbs derived from other species currently used.
One of the advantages of the phage display technology is that it is not necessary to immunize the donor with the Ag of interest to isolate human mAbs. However, purification of the Ag is normally needed for the screening of human mAbs libraries. Proteins (such as membrane proteins, nuclear proteins, cytosolic proteins, and recombinant proteins) have been purified by column chromatography or affinity chromatography techniques from eukaryotic cells, insect cells, bacterial cells or their culture supernatant. Although advanced biochemistry and biotechnological approaches permit the availability of a large variety of Ags in purified form, such proteins sometimes may not maintain the correct conformation and are easily disrupted by biochemical manipulation. In addition, the purification of Ag can be laborious, complicated and time-consuming especially when the Ag is in low abundance.
Creative Biolabs’ Ab-guided selection strategy using capture-sandwich ELISA can successfully overcome this problem. Using two separate Abs to capture and detect Ags, Sandwich ELISA has been widely used for specific detection of target Ags from crude preparations. We have applied a similar principle to a panning procedure by using a crude Ag preparation if an appropriate Ab specificity against the Ag of interest is available. In the procedure, the displayed phage library replaces the second detection Ab. Both mAbs and polyclonal Abs can be used as capture Abs. We do not need to purify the target Ags, and Abs against conformation-sensitive Ags can be selected.
Fig.1 Outline of the panning procedure for enrichment of Ag-speciﬁc phage Ab by Ab-guided selection using a capture sandwich ELISA (Kunihiko Itoh et al. 2002).
Creative Biolabs’ scientists have extensive experience in phage display library screening based on Ab-guided selection using a capture-sandwich ELISA. By using capture Abs with varying specificities, mAbs against a variety of Ag epitopes can be isolated from a single library.
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