Incident light fluorescence microscopy is growing rapidly in importance as an investigational tool in the fields of medical and biological research. All photomicrographs in this gallery were taken with Olympus microscopes employing UIS optics and a PM-30 automatic camera system.

The specimen is human lung carcinoma epithelial cells grown in monolayer tissue culture and double-stained to expose microtubules and actin filaments using a mixture of FITC and rhodamine-phalloidin. Photomicrographs were recorded utilizing a UPL 40x fluorite objective coupled to a WIBA/WIG dichroic filter combination. A 3.3x projection photo eyepiece was used to transfer light from the intermediate image plane to the photographic emulsion.

Microtubules are straight, hollow cylinders are found throughout the cytoplasm of all eukaryotic cells (prokaryotes don't have them) and perform a number of functions. These macromolecular complexes form part of the cytoskeleton that gives structure and shape to a cell, serve as conveyor belts moving other organelles through the cytoplasm, are the major components of cilia and flagella, and participate in the formation of spindle fibers during cell division (mitosis). Microtubules can function individually or join with other proteins to create larger structures (e.g. cilia). The individual filaments are composed of linear polymers of tubulin, which are globular proteins, and can increase or decease in length by adding or removing tubulin proteins.