When combinatorial chemistry emerged in the early nineties, miniaturiz
ation was a prerequisite for many breakthrough approaches. A wave of s
cale-up development ensued, driven by the need to interface this techn
ology with classical medicinal chemistry. A renaissance of the microsc
opic perspective is now taking place, motivated by the implementation
of increased throughput screening and the application of concepts and
hardware from the diagnostics and genomics sectors. The author describ
es the different approaches of wet-chip technology with reference to t
he generation of molecular diversity.