Molecular OS Gets Upgrade

The field of molecular computing came to prominence in 1994 when Len Adleman described a DNA computer based on PCR (Science, 266:1021–4). Such computers could be useful for solving particular problems but are fairly inflexible. "The main problem is that PCR can amplify the wrong DNA sequences, so errors can build up and large useful computations are difficult to perform," says Thomas Schneider of the National Cancer Institute's Laboratory of Experimental and Computational Biology.

Schneider and colleagues came up with a molecular computer that uses such elements as "flip-flops" (two-state devices that can store one bit of information) and logic gates (which solve binary problems such as AND, OR, NOR, and NOT) comprising proteins and nucleic acids. The method, recently awarded US patent 6,774,222, relies upon nucleic acids designed with two or more protein-binding sites for the same protein, such that factor binding is mutually exclusive: If site...