Printing protein arrays from DNA arrays.

We describe a method, DNA array to protein array (DAPA), which allows the 'printing' of replicate protein arrays directly from a DNA array template using cell-free protein synthesis. At least 20 copies of a protein array can be obtained from a single DNA array. DAPA eliminates the need for separate protein expression, purification and spotting, and also overcomes the problem of long-term functional storage of surface-bound proteins.