The index is set to replace the Dow average on April 8 as the index whose action will be monitored for the sharp swings that trigger "circuit breakers" halting all U.S. stock trading.

WSJ: S&P 500 Milestone Has More Meaning Than Dow Record for Many

It can then interact with other strands, chopping them to trigger other gates or activate fluorescent tags that display the circuit's final output.

ECONOMIST: DNA computing