 Without methods to account for this "context dependence", the standard modular assembly procedure often fails unless it is used to recognize sequences of the form (GNN)N.

Numerous selection methods have been used to generate zinc-finger arrays capable of targeting desired sequences.Initial selection efforts utilized phage display to select proteins that bound a given DNA target from a large pool of partially randomized zinc-finger arrays.More recent efforts have utilized yeast one-hybrid systems, bacterial one-hybrid and two-hybrid systems, and mammalian cells.