LED Illumination to Eliminate Shutter Vibration Noise

Did you know that using LED illumination can eliminate shutter vibration noise? The following figure was created by a Prizmatix customer to illustrate this advantage:

Here is one figure that shows the problem that your LED illuminator solved for us. The figure shows a neuron in a slice filled with a calcium indicator dye. We measure the fluorescence as a function of time in different parts of the cell as an indication of how the calcium concentration changes as a function of time. We used a 75 Watt xenon arc lamp and a Uniblitz shutter to control the illumination period. For example, the trace on the right shows the average fluorescence in the red box over a period of about one second after the shutter was opened. For the first several hundred milliseconds there is an oscillation. This oscillation was due to mechanical vibrations caused by the opening of the shutter. The oscillation was significant – about 2 %. Later the oscillation damps down.

The figure below shows a similar experiment using your LED illuminator. In this case there was no vibration because the light was controlled by an electronic pulse.

The images in both figures were taken with a very high speed camera (500 frames per second). This camera has only 80x80 pixels, which explains why you can see the pixels in the images.

We also found that for exciting fluorescence of OGB-1 (the calcium indicator that we are using) that the LED evoked about twice the fluorescence intensity as the 75 Watt xenon arc lamp we usually use.