Using strands of DNA as movable type, scientists have created a miniaturized printing technique for mass-producing medical-diagnostic chips.
In the technique, developed by Francesco Stellacci of the Massachusetts Institute of Technology (MIT) and his colleagues, scientists attach thousands or millions of customized DNA strands to a gold chip in a specific pattern. This becomes the master chip.
To mass-produce DNA chips, the researchers dunk the master into a solution containing sequences of DNA that are complementary to the strands on the master and are capped with a chemical that binds to gold. After the complementary strands bind to their DNA cohorts on the master, their ends adhere to a second gold surface gently pressed against the chip. Heating the entire complex causes the paired DNA strands to separate, yielding a new chip and liberating the master to be used again.