DNA microarrays are widely used in many areas of biological research. They are an efficient tool for gene expression analysis due to a high level of parallelism, what means that they allow for simultaneous measuring of the transcriptional activity of all genes present in the studied genome. The quality of the results obtained using microarrays depends among other factors on the proper design of probes. Two general features which should characterize each probe are sensitivity and specificity. Since designing a set of probes having both of these properties is usually a complex task, many algorithms supporting this process have been developed and implemented. However, the designing method should be carefully chosen such that the results will match the requirements following from the nature of the biological problem to be solved. In this paper the criteria used for DNA microarray design are described and some computer based approaches are presented.