Optical tweezer attaches single DNA molecule to silicon

As part of a demonstration that single polymers can be attached to specific sites on silicon, researchers at Rockefeller University (New York, NY) have developed a noninvasive approach to selectively graft DNA polymers onto a silicon substrate. The researchers used the combination of an atomic force microscope (AFM), an optical tweezer based on an 830-nm-output laser diode, and an optical microscope. Success resulted from first attaching a single DNA molecule to a latex bead in water. The optica

Feb 1st, 1998

Optical tweezer attaches single DNA molecule to silicon

As part of a demonstration that single polymers can be attached to specific sites on silicon, researchers at Rockefeller University (New York, NY) have developed a noninvasive approach to selectively graft DNA polymers onto a silicon substrate. The researchers used the combination of an atomic force microscope (AFM), an optical tweezer based on an 830-nm-output laser diode, and an optical microscope. Success resulted from first attaching a single DNA molecule to a latex bead in water. The optical tweezer then traps the bead. The AFM comes into contact with the bead while the laser remains on the bead to attach it to the AFM cantilever--which is a silicon substrate.

The technology promises a more general and powerful method of depositing single DNA molecules using heat instead of chemicals, which are usually specific only to certain surfaces or sites. Graduate student and team leader G. V. Shivashankar says that there is a significant advantage in assembling biological molecules such as DNA and proteins at the micron scale and that his group`s work on DNA is only one example of the potential applications. Although the technologies to implement them are not yet available, applications could include microfabrication of biochips and assembly of polymer interconnects or other devices for bioelectronics.

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