Polyclonal vs Monoclonal antibodies

http://en.wikipedia.org/wiki/Antibody

Specific antibodies are produced by injecting an antigen into a mammal, such as a mouse, rat or rabbit for small quantities of antibody, or goat, sheep, or horse for large quantities of antibody. Blood isolated from these animals contains polyclonal antibodies—multiple antibodies that bind to the same antigen—in the serum, which can now be called antiserum. Antigens are also injected into chickens for generation of polyclonal antibodies in egg yolk.[51] To obtain antibody that is specific for a single epitope of an antigen, antibody-secreting lymphocytes are isolated from the animal and immortalized by fusing them with a cancer cell line. The fused cells are called hybridomas, and will continually grow and secrete antibody in culture. Single hybridoma cells are isolated by dilution cloning to generate cell clones that all produce the same antibody; these antibodies are called monoclonal antibodies.[52] Polyclonal and monoclonal antibodies are often purified using Protein A/G or antigen-affinity chromatography.[53]

http://www.abcam.com/index.html?pageconfig=resource&rid=11269&pid=11287

Polyclonal antibodies - multiple antibodies that bind to the same antigen

Facts:

* Recognise multiple epitopes on any one antigen. Serum obtained will contain a heterogeneous complex mixture of antibodies of different affinity
* Polyclonals are made up mainly of IgG subclass
* Peptide immunogens are often used to generate polyclonal antibodies that target unique epitopes, especially for protein families of high homology

Antibody production:

* Inexpensive to produce
* Technology and skills required for production low
* Production time scale is short
* Polyclonal antibodies are not useful for probing specific domains of antigen because polyclonal antiserum will usually recognize many domains


Monoclonal antibodies

Facts:

* Detect only one epitope on the antigen.
* They will consist of only one antibody subtype. Where a secondary antibody is required for detection, an antibody against the correct subclass should be chosen.

Antibody production

* High technology required.
* Training is required for the technology used.
* Time scale is long for hybridomas.