Protein Microarrays

Protein–protein interactions can be analyzed with the use of protein microarrays, which are similar to the microarrays used for examining gene expression. With this technique, a large number of different proteins are applied to a solid support as an orderly array of spots, with each spot containing a different protein. In one application, each spot contains an antibody for a different protein and is labeled with a tag that fluoresces when bound. An extract of tissue is applied to the protein microarray. A spot of fluorescence appears when a protein in the extract binds to an antibody, indicating the presence of that particular protein in the tissue.