Assay of proteins

An appropriate means of detecting assaying the protein must be available to monitor the success of every stage in the purification process. The most straightforward   assays   are those for enzymes   which catalyze   reactions   with readily detectable products. Proteins  that  are  not  enzymes  may  be  assayed  by  the  observation  of their biological effects. For instance, a receptor can be assayed through measuring its ability to connect its specific ligand.  Immunological  methods  are frequently  used  to assay  for the protein  of interest  using  antibodies  which  speci?cally  recognize  it for instance enzyme-linked   immunosorbent    assay   (ELISA),    radioimmunoassay or Western blot analysis.