Confocal Microscopy with Transmitted Light
Although confocal reflection (brightfîeld) and fluorescence microscopy have found widespread use in biology, scanning transmission microscopy has been explored and implemented only infrequently, and a single-pass scanning confocal transmission microscope is still not available as a commercial product. This might indeed be considered surprising, since biologists have long known the advantages of observing an enormous variety of specimens (e.g., stained or unstained, preserved or living) using conventional light microscopes with their wide range of transmission modes such as brightfîeld, phase-contrast, or differential interference contrast (DIC). The fact that confocal transmission modes are not generally available is partly due to the fact that most biological preparations have a complex mixture of optical properties that create regions of varying refractive index (η) and absorption. These can introduce sufficient aberration and deflection into the transmitted wavefront to make it very difficult to keep the transmitted beam aligned with a standard pinhole detector as it scans over the specimen.
KeywordsMicroscope Objective Transmission Image Transmitted Beam Reflection Image Wollaston Prism
Unable to display preview. Download preview PDF.
- Art, J.J., Goodman, M.B., and Schwartz, E.A., 1991, Simultaneous fluorescent and transmission laser scanning confocal microscopy, Biophys. J. 59:155a.Google Scholar
- Brakenhoff, G.J., 1979, Imaging modes in confocal scanning light microscopy (CSLM), J. Microsc. 117:232–242.Google Scholar
- Cogswell, C.J., and Sheppard, C.J.R., 1989, Imaging using confocal brightfield techniques, Inst. Phys. Conf. Ser. 98:633–638.Google Scholar
- O’Byrne, J.W., and Cogswell, C.J., 1992, A high resolution confocal transmission microscope: II. Determining image position and correcting aberrations, Proc. SPIE 1660:12–520.Google Scholar