New optical tweezers can use existing microscopes

July 30, 2008--Elliot Scientific has added new systems to its range of optical tweezers; the new systems offer the ability to retrofit existing microscopes and bring optical tweezing into the lab at an affordable price, says the company.

July 30, 2008--Elliot Scientific has added new systems to its range of optical tweezers; the new systems offer the ability to retrofit existing microscopes and bring optical tweezing into the lab at an affordable price, says the company. Optical tweezers (also called laser tweezers) have found many applications in the sciences, such as DNA property measurement, particle spectroscopy, and cell sorting, but until now have been confined to use with specialized, complicated microscopes.

The company's new single-spot system is designed for trapping and manipulation of micron-sized particles; it is called the E3300. It includes an optical module containing the laser, beam steering optics, and the microscope interface. The optical module attaches to the microscope either through an additional unit, such as an epi-fluorescence attachment, or a camera port.

The laser beam containing the trapped particle can be directed anywhere within the field of view by manually steering the conjugate optics. Alternatively, the particle can be held trapped in place and the bulk sample moved around it using the microscope X-Y stage. For applications involving rotation of birefringent particles, an optional polarization optic and rotation mount can be added.

Elliot Scientific is also introducing a multiple-beam system, the E3400, for users who want to undertake multiple-beam particle-trapping and manipulation experiments. Unlike the E3300, beam control on the E3400 is provided by high-speed acousto-optic deflectors driven by a computer-controlled module. The supplied software is designed to allow for the creation and independent manipulation of multiple optical traps anywhere within the field of view in X and Y directions. A high-speed GigE interface camera allows visualization of the particles.

Traps are created and positioned in the software by mouse control. They can be single spots, lines, or circular arrays. The spacing, orientation, and number of traps can be adjusted via the control panel and traps can be added or removed at any time without affecting the existing ones. Multiple arrays and spots can be manipulated independently of each other (ample movies showing this in action are available to view and for download from www.elliotscientific.com).

A range of interfaces for both systems are available dependant on the make and model of microscope.

For more information, contact Colin Freeland, product manager: colin.freeland@elliotscientific.com

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