manipulation of microscopic specimens using micro-sized equipment such as optical tweezers
The need to perform delicate manipulation of a specimen under the microscope has led to the development of precision microtools (micromanipulators) such as holding pipettes, injectors, and cutting tools. The requirement for precision movement in the x, y and z direction with sub-micron resolution has created a range of mechanical, hydraulic and electric devices designed to deliver accurate, smooth and controllable movement. Micromanipulation has not only required the development of specific micro-tools but has also demanded modifications in microscope design. A stable, vibration-free microscope environment is essential for precision work, as is the requirement for enough room around the specimen to position micromanipulation equipment. Long working distance objectives are required to allow the insertion of micromanipulation equipment below the microscope objective.
As an alternative to mechanical methods of micromanipulation, the technique of optical tweezers has evolved in recent years. This relies only on the properties of light to trap and move objects, avoids mechanical contact with the specimen, and enables precise manipulation of individual molecules or even atoms.
Micromanipulation is most widely employed in the fields of electrophysiology, IVF, transgenics and adherent cell micromanipulation. The technique of optical tweezers is used, in particular, to study the movement and physical properties of molecules and cells. It is also used in industrial environments to study metal particles and colloids.
Micromanipulation can be carried out using both inverted microscopes and upright microscopes.
Nikon's FN1 is a special purpose upright microscope designed for electrophysiology and the most demanding of micromanipulation tasks. The objectives boast a long W.D. of 2.5-3.5mm, are 17% slimmer than previous lenses, and provide broad approach angles up to 45º facilitating enhanced access of microelectrodes to the specimen. A simple body design provides more space in the working area for the positioning of manipulators and other peripherals. A wide variety of Narishige micromanipulators are available, from motorized hydraulic to oil-type. They are all of compact design and can be easily and solidly mounted to the ITS-FN1 stage.