DNA microarrays for detecting genetic diseases will be easier and cheaper to produce thanks to scientists in the US. 

Francesco Stellacci and colleagues at the Massachusetts Institute of Technology have developed a method they call supramolecular nanostamping that allows spatial and chemical information to be transferred from one surface to another.  They say nanostamping can be used to print DNA microarrays.

DNA microarrays consist of thousands of dots of DNA spotted onto a glass or polymer plate a few centimetres in size. Each dot contains DNA molecules of a particular sequence.  The arrays can be used to screen thousands of DNA sequences which recognise and bind to their complementary strand on the plate. DNA microarrays are promising devices for analysing human genes but are made through long and costly processes, said Stellacci.

Stellacci's nanostamping method uses a master plate with single stranded DNA molecules attached to the plate by one end. When the plate is dipped into a solution of complementary DNA strands, they hybridise with the strands attached to the plate, and then bind to a second plate. The second plate can be pulled away to give a DNA array complementary in sequence and spatial arrangement to the first. The process can be repeated using the second plate as the master to produce an exact copy of the original.

Henry Smith, professor of electrical engineering at MIT, worked with Stellacci to develop the technique. 'This is a first step in the development of a generic technology for achieving highly functional nanosystems based on macromolecules. We know from living systems how powerful such nanosystems can be,' said Smith.

Michael Smith