Leica AM TIRF
Innovative Development in Fluorescence Simplifies Complex Microscopy Method
15 June 2006: Total Internal Reflection Fluorescence (TIRF) is an excellent tool for the functional
examination of processes in living cells. In this method, fluorophores are excited using an evanescent field generated by total reflection. The Wetzlar, Germany-based optics manufacturer has developed a scanner technology for TIRF that greatly simplifies this otherwise very complicated technique.
With the Leica AM TIRF, users can concentrate completely on their research work, while leaving instrument operation up to a powerful software program. Vesicle transport examinations, analysis of interactions
between molecules, applications in membrane research and even single molecule examinations
can be tailored to specific needs using the Leica AM TIRF.
The software-controlled TIRF scanner automatically
finds the correlation between the penetration depth of the evanescent field and the corresponding TIRF angles.
With the Leica AM TIRF, complicated manual settings and complex calculations are unnecessary—the intelligent Leica AF6000 fluorescence software assumes these tasks, making the system convenient and easy to use.
Furthermore, various penetration depths can be reproduced at any time, and the laser beam can be
rotated within the inlet pupil of the objective in order to generate various directions of the evanescent
field. With the Leica AM TIRF, all contrast methods are possible, either simultaneously or sequentially.
For example, transmitted light and fluorescence, or DIC and TIRF, can be combined easily with each
other.
The evanescent field penetrates the specimen only to a depth of approximately 100-300nm. All of the
fluorophores at a greater depth in the specimen remain inactive. Thus the TIRF method allows a significantly better signal-to-noise ratio than widefield fluorescence microscopy. TIRF also achieves higher resolution in the z-axis. Normally, the axial resolution of a high-end objective is physically limited by the
wavelength of the light being used to about 200-300nm. The highly accurate TIRF excitation of 50-
300nm in the z-axis bypasses this physical limitation. Furthermore, the excitation of the fluorochrome using an evanescent field reduces bleaching on the specimen. The cells are not directly exposed to laser light.
The Leica TIRF module, which consists of a Leica HXC planapochromatic objective with a numerical
aperture of 1.46 and the high-performance scanner that can be moved in three dimensions, can be
adapted to various inverted microscopy systems from Leica Microsystems. Microscopes available in the widefield area, adapted to individual needs and requirements, are the Leica DMI6000 B fully automated research microscope, the semi-automated DMI4000 B and the Leica AF6000 LX multidimensional
fluorescence workstation. Alternatively, Leica offers two confocal systems: The Leica TCS SPE entrylevel system and the TCS SP5 high-end system.
For further information, please contact:
Miss Candice Fauter
Marketing
Leica Microsystems (UK) Ltd
T: +33 1 47 32 85 11
F: +33 1 47 32 85 53
E: candice.fauter@leica-microsystems.com
W: http://www.leica-microsystems.com |
