Brainvision Inc. has released the new LED-5G and LED-5B, both high-power LED illumination systems for fluorescent imaging. They can be used by as stand alone light sources, or they can be easily adapted to microscopes.

Xenon and Mercury light sources have problems such as flicker and bulbs with short life-times. Halogen bulbs provide more stable lighting with reduced noise, but these bulbs also have a very short lifetime. However, LED's can last for several years, up to 10 years in some cases, if the temperature is controlled. Furthermore, its intensity is stable and does not produce any flicker. Electrical on/off vibration-less shutter is also one of the reasons why these LEDs are an ideal illumination source for high speed imaging.

The right figure shows the rise time and fluctuation of LED light intensity, detected using the MiCAM ULTIMA-L high speed camera at the 0.1msec/frame and 100x100 pixels. The horizontal and vertical axes indicate time (1msec/div) and LED light intensity (%age) respectively. Within the first 0.3 milliseconds after the LED is turned on, the intensity reaches 95% of its maximum brightness. The LED emits maximum brightness only 3 milliseconds after it is turned on and continues to illuminate at a stable intensity. In this condition, the small fluctuation of light intensity is smaller than the photon shot noise. These results indicate that the high-power LED light source is suitable not only for high-speed fluorescence imaging, but for a wide range of experiments using various fluorescence probes.

LED-5G and LED-5B can be easily adapted on the THT tandem-lens microscope from Brainvision or SciMedia, and can also be used on any fluorescent microscope.