DNA microchip

The so-called DNA microchip, a particular type of diagnostic chip, is a microarray consisting of a grid of sensors capable of recognising particular sequences of genetic material. Chips of this kind are employed in genetics to provide early diagnosis of illnesses such as Alzheimer's disease, AIDS and certain types of cancer.

The yet smaller DNA nanochip makes it possible to analyse samples as small as a single cell, eliminating the need to rely on traditional PCR techniques to propagate the genetic material being analysed, which can introduce errors.

The first DNA nanochip prototypes were manufactured at the Elettra Laboratory, and at CNR IOM, by means of a nanolithography technique based on the atomic force microscope (AFM). These chips consist of a matrix of squares, each a few tens of nanometres in size and containing a specific sequence of tightly packed oligonucleotides. By using a technique for the replication of DNA that exploits its ability to hybridise with sequences complementing those held in the matrix, innumerable copies of the original device can be produced. The exceptional sensitivity of this device allows extremely small quantities of DNA to be analysed at a cost kept relatively low by the hybridisation technique.