The development of protein microarrays makes possible interaction-based protein assays in miniaturised, multiplexed formats. A major requirement determining their uptake and use is the availability and stability of purified, functional proteins for immobilisation. With conventional methods, involving individual expression and purification of recombinant proteins, the cost of commercial high-content protein arrays is often found to be prohibitively high. Moreover, due to the need for specialised microarray production equipment, custom-made protein arrays containing more focussed sets of proteins of interest are also in little use. In the DNA array to protein array technology described herein, repeated economical printing of protein microarrays from a reusable template DNA microarray is performed on demand by cell-free -protein synthesis. Once the template DNA microarray has been obtained, protein microarrays are made using purely macro-handling procedures, making protein arraying accessible without sophisticated microarraying apparatus.