title: Zero-cost modification of bright field microscopes for imaging phase gradient on cells: Schlieren optics.
abstract: A simple, zero-cost, reversible modification of a bright field microscope permits visualization of phase gradients in cells by transmitted illumination, yielding a Nomarski-like effect. This modification, based on schlieren optics, is simultaneously compatible with high-aperture epi-illumination fluorescence excitation. For many objectives that are intended for use in fluorescence work, but are unavailable in phase contrast versions, the modification provides a simple means for locating cells in culture with good image contrast and resolution.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003365:Costs and Cost Analysis; D006801:Humans; D008029:Lighting; D008853:Microscopy / Q000295:instrumentation*; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D008858:Microscopy, Phase-Contrast / Q000295:instrumentation*; D009061:Mouth Mucosa / Q000166:cytology; D009132:Muscles / Q000166:cytology; D055095:Optics and Photonics; D051381:Rats