Protein chips approach.

Differential display can also be studied by using protein chips approach, where a variety of 'bait' proteins such as antibodies are immobilized onto specially treated surfaces, in an assay format (just like DNA chips. The surface is then probed, with the sample of interest, so that only the proteins that bind to the 'baits' (e.g. antibodies) remain bound to the chip. This is large scale version of ELISA. In this approach, cell lysates may be labelled by different fluorophores and the mixture is used as a probe for the protein chip, so that colour acts as a readout for any differential display of proteins in the two cell lysates. MALDI may also be coupled with protein chips to allow direct MALDI readout of the bound proteins to identify proteins showing differential display.