Both polyclonal and monoclonal antibodies have their own advantages and disadvantages,
making them useful for different research applications.
Polyclonal Antibodies
Polyclonal antibodies (pAbs) are comprised of a mixed population of antibodies
and are therefore capable of recognizing multiple epitopes on any one antigen.
Advantages:
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Can help to increase the signal produced by the target
protein as the antibody will bind to more than one epitope.
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More tolerant of minor changes in the antigen, e.g.
polymorphism, heterogeneity of glycosylation, or slight denaturation.
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Useful when the nature of the antigen is unknown.
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More robust detection due to multiple epitopes.
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Generally more stable, quick and inexpensive to produce
compared to mAbs.
Disadvantages:
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Prone to batch-to-batch variability.
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Susceptible to cross-reactivity with immunogen due to
recognition of multiple epitopes.
Monoclonal Antibodies
Compared to pAbs, mAbs are more specific because they stem from a single
antibody clone and thus recognize a single epitope on an antigen.
Advantages:
-
Hybridoma cell lines provide a way to produce unlimited
quantities of homogenous, highly specific mAbs.
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If conditions are kept constant, experiments using mAbs can
be highly reproducible.
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All mAb batches will be identical and specific to just one
epitope, which is a critical advantage when manufacturing procedures must be
standardized e.g. clinical tests and therapeutic treatments.
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High specificity, as well as low background noise and
cross-reactivity ensures high mAb efficiency and reproducibility in experimental
procedures (western blot/IP, affinity purification, ELISA, mass spectrometry etc.).
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Specific antibody characteristics can be identified and
selected for. For example, sensitivity requirements and cross-reactivity levels can
be specified and monoclonal antibodies screened to identify any cell lines
exhibiting the required characteristics.
Disadvantages:
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mAbs may be too specific (e.g. less likely to detect across a
range of species).
-
More vulnerable to the loss of epitope through chemical
treatment of the antigen than polyclonal antibodies. This can be offset by pooling
two or more monoclonal antibodies to the same antigen.
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Compared to pAbs, mAbs are more expensive and take longer to
produce.