In each high-density experiment, a series of consequent steps is applied in a laboratory to produce the final product that becomes a source of the data to analyze (a microarray slide with hybridized DNA of samples, 2-D gel with serum …). Different ways of production exists, but there are some common steps that have to be followed in order to achieve the desired result. This applies also for the data analysis part of the experiment. We can draw a basic data analysis workflow that is common for each high-density genomic or proteomic experiment. The following figure shows such a workflow. This workflow is usually adjusted it according to the type of the experiment and the objectives to be achieved.