Available from Omega Optical is the FRET technical application note “Optimizing Filter Sets for FRET Applications.” Downloadable from the company Web site, the four-page document begins with an overview of the Förster resonance energy transfer phenomenon. In a discussion on filters and microscope configurations, it notes that two emission filters are required for the process — for the acceptor and for the donor fluorophore. Multiview attachments that produce a simultaneous split-screen view of the sample are covered, along with automated emission filter wheels and separate filter cubes.