CONFOCAL THETA MICROSCOPE WITH 3 OBJECTIVE LENSES

A microscope using three water immersion objective lenses which realiz es confocal, 4Pi-confocal and various confocal theta microscopies in f luorescence, transmission, scattered, and reflection mode is described . An argon-ion laser is the primary light source. A pulsed titanium-sa pphire laser allows two-photon absorption fluorescence microscopy. The instrument has a predicted resolution of 100 nm along the illuminatio n axis and a three-dimensional resolution of 5 x 10(6) nm3 for lenses each with a numerical aperture of 0.75. This is an improvement of an o rder of magnitude over a confocal fluorescence microscope using the sa me lens. Applications of the microscope range from observation of a sa mple at three different angles, to confocal theta fluorescence microsc opy with multiphoton absorption. Since mounting and immersion media ar e identical, aberrations become negligible. The large working distance of 2 mm makes the instrument ideal for the observation of biological samples of up to 1.5 mm in diameter such as drosophila embryos.