The Fast Filter Wheel Accessory, is used for rapid collection of data in the study of biochemical processes such as intracellular ion monitoring. Pairs of optical filters specifically designed for the indicator dyes are rapidly rotated in either the excitation or emission beam, allowing ratio measurement to be made every 40 msec. Two pairs of filters can be fitted on each wheel allowing for example, the simultaneous measurement of both calcium and pH using a pair of FURA-2 and BCECF filters. The Fast Filter Application Software, which is similar to the Intracellular Biochemistry program, is used to control the accessory. It provides the facility to set up methods, collect data, and calibrate the result. Either the ratio data or the individual intensities can be viewed in real time. The data are automatically saved as ASCII files and a full numerical report can be printed out. Includes the Fast Filter Accessory Boards and Software(L2250019) and one Drive Unit (L2250146). Requires, but does not include, a filter set. Requires, but does not include, installation by a PerkinElmer Service Engineer.