Phase Contrast Imaging
Phase Contrast is a contrast enhancing optical microscopy technique in which an unstained transparent sample is seen with high brightness by shifting phase difference of light.
The idea of Phase Contrast Imaging was brought by Frits Zernike in 1930's, a Dutch physicist, who got the Nobel prize in 1953 for this invention.
Phase contrast is mainly used by biologists and has some advantages over brighfield imaging. Using phase contrast microscopy, many cellular structures that cannot be seen by a brightfield imaging become visible, without staining.
Phase Contrast Microscopes
Phase Contrast microscopes are mainly offered in biological microscopes and for transparent samples only. Opaque /or non-transparent samples need DIC Nomasrky Imaging technique. Thus, biological microscope either upright or inverted comes with extra accessory for Phase Contrast imaging. This needs a condenser, phase contrast objective lens and annulus plate.
Phase contrast imaging is a great techniques for live blood cell analysis.