How to build a super-resolution microscope
A super-resolution microscope, PALM (sometimes called STORM), provides a fluorescence image with high spatial resolution on the order of 10 nm. The set-up of PALM is very simple; therefore, you can easily build it by yourself. A home-made PALM system costs only 20-40 % of a commercial system. Here we describe how to build your own super-resolution microscope. The right figure shows the block diagram of the optical system of PALM. Co-linearly overlapped laser beams are introduced to the excitation illumination port of a microscope and the fluorescence signal from the sample is imaged onto a CCD camera through optical filter. Details on the components of the system and the procedure to build it are below.Equipment
Setup of optics
Setup of electronics
Place shutters in the beam path to control the timing of the illumination.
The camera exposure and the laser illumination should be synchronized by a trigger signal from a pulse generator. Wire the trigger inputs of the camera and lasers to the output of the pulse generator.
Program the sequence of the trigger signal. An example of the pulse sequence is below, where the high state corresponds to he open state of the shutter. The pulse length should be changed dependent on the measurement condition. The excitation laser is operated in CW.
In this example, the camera and lasers are driven by the pulse generator. If the camera outputs timing signals, it can be used as the master clock for the illumination control.
Check the output pulse by an oscilloscope and test the synchronization of the camera and lasers.
If you have questions and comments, please send an e-mail to hiroyuki.aoki(_at_)j-parc.jp .