How do you perform precipitation and agglutination?I am trying to understand the concepts of both from a microbiological stand point.

Both precipitation and agglutination are immunoassay
techniques that involve using the antigen - antibody complex to identify and separate
proteins.

For immunoprecipitation, one must first label the
sample by adding a marker element or radioisotope. The sample is then incubated with the
antigen, and antigen - antibody complexes are allowed to form. The complexes are then
passed across a separation plate which contains a bound protein which has a high
affinity for the antibody - antigen complexes. The complexes are separated from the
bound protein by centrifuging, heating to disrupt the protein, or pH adjustment, and are
collected.

Agglutination is a simpler version of the same
technique. To do it you mix an agglutinin with a liquid blood sample, and if the
corresponding protein is present in the sample, you will see clumping. It is useful as a
rapid diagnostic test for things such as blood group
typing.

If you need more details on the techniques, you
will find an excellent reference from Tulane University href="http://www.tulane.edu/~wiser/methods/notes.pdf">here.