The Biomek 2000 Laboratory Automation Workstation is used for liquid handling and other repetitive operations in many laboratories. Since it has very good spatial positioning capabilities, we have modified this workstation to deliver samples at high densities onto microscope slides to produce DNA microarrays. The workstation tool, originally designed for bacterial colony replication, was adapted to carry special printing pins and was further modified to improve its positional accuracy. Software written in the Tool Command Language was concurrently developed to control the movements of the workstation arm during the process of printing. With these modifications, the workstation can reliably deliver individual samples at a spacing of 0.5 mm, corresponding to a total of more than 3000 samples on a single slide. Arrays prepared in this way were successfully tested in hybridization experiments.