In this paper, we describe a method for replication of DNA microarrays. The approach involves in situ, enzymatic synthesis of a DNA complement array using a prefabricated master array, followed by mechanical transfer of the complement array to a second substrate. The new findings reported here include the following. DNA spots as small as 100 μm can be faithfully replicated, replica arrays consisting of several different oligonucleotide sequences can be prepared, and such arrays are active toward hybridization of their complements. Up to 10 replicas can be prepared from a single master with no detectable progressive degradation of their activity. DNA master arrays consisting of long DNA templates (80-mer) can be replicated, as can large-scale master arrays consisting of 2300 spots.