The Cairn Optospin fast stepping / spinning filter changer (a.k.a. the rotor) is designed with both photometric and imaging systems in mind. It can be configured with either three or six filter positions, allowing for simultaneous use of several dyes. Unlike previous versions of "the rotor" the Optospin accepts 25mm filters making it suitable for both excitation and emission wavelength changing. The microprocessor control unit allows the operation to be "tuned" to the application, giving fine control over the acceleration speed, degree of damping etc.
Continuous spinning mode is our recommended rotor based solution for photometric measurements, and rotor speeds from less than 2 to over 100 revolutions per second are routinely possible with this system. Each filter position can also be discontinuously selected, with switching times of 35msec between adjacent positions or 55msec between opposite wheel positions. The low end of the spinning speed range allows synchronous spin with a video camera at normal frame rates and the discontinuous stepping mode is ideally suited to wavelength selection for imaging applications.
- Proprietary external coil motor design for maximum torque. The Cairn Optospin rotor does not use a motor - it is a motor!
- Continuous spinning operation at speeds from 2 up to >100 revs/sec.
- Precise rotor speeds selectable via the on board frequency generator, or by direct synchronisation to an external source.
- Worst case transition times in discontinuous mode of 55msec, with transitions between adjacent filters taking under 35msec.
- Full control using hardware or software as part of a photometry or imaging system or as a standalone product.
- Six position Optospin allows simultaneous recording with different dual excitation dyes (e.g. fura-2 and BCECF).
- The quoted filter changing times are for a combined photometry / imaging assembly; dedicated imaging filter changers can be optimised to attain even more rapid response.
The rotor assembly is controlled directly from the front panel of its system rack or by one of two digital interface options.
- All systems have a simple TTL interface connector which is designed to allow the rotor to be controlled externally. This is especially useful for imaging applications or other third party products (e.g. software from Universal Imaging, Kinetic Imaging and Improvision). This interconnection is made with a standard 37 way D connector. A suitable method of control is from a PC parallel port and a cable; a Windows driver DLL is available for this purpose.
- Using an RS232 serial link to take over full operation of the microprocessor control rack.