DNA chips

compare two states of a cell (e.g. healthy-disease) with regard to expression of genes

Example: plus-minus glucose

Types of information available from the experiment:

color:    red (-glucose): starved cell

             green (+glucose): healthy cell

color plus position:         red dots: proteins expressed more in starved cell

                                        green dots: proteins expressed more in healthy cell

                                        yellow dots: proteins equally expressed in both cells

intensity:    high - highly expressed

                  low - little expressed