Ratiometric calcium imaging with microsecond switching
Compact and optimised LED light source for 340nm / 380nm or 360nm / 405nm ratiometric Fura-2 or Fura-8 fluorescence imaging
Ratiometric calcium imaging with LEDs can work extremely well, but, due to the relatively narrow bandwidths and spectral variations of individual LEDs, it does require attention to detail. The FuraLED head works directly with our OptoLED controller and makes the process simple, as we take care of the LED selection, intensity regulation and bespoke optics to make your experiments work with the best possible signal-to-noise. We offer a choice of conventional Fura-2, or the red-shifted Fura-8, enabling the use of standard Plan Apo lenses, which don’t transmit light at 340nm. High and low affinity versions of both dyes are available from AAT Bioquest allowing the accurate recording of fast and slow calcium changes..
We understand that most researchers will also want to use visible indicators and, quite likely, their existing lightsource alongside the FuraLED. To simplify this the coupling is equipped with a straight-through port to accommodate any fibre based illuminator, or additional Cairn LEDs.
Cairn have supplied Fura-2 systems for three decades now. The company was founded on a photometry system comprising of a spinning filter wheel illuminated by a xenon arc light source. More recently (last 18 years) we have been selling the Optoscan monochromator, still illuminated with a xenon arc light source, but using a diffraction grating mounted on a galvanometer. We introduced an LED light source for Fura2 five years ago, but only with 360nm isosbestic ratioing (due to limitations in LED availability). We are delighted to now offer full 340nm / 380nm ratiometric Fura-2 imaging with integrated excitation filters. Similarly, the LED configuration for fura-8 is also available.