Scientists employ a variety of imaging technologies to visualize and analyze cells on a microscopic level - to reveal what is imperceptible by the naked eye.
These technologies include the classical optical microscope, electron microscopy and laser scanning microscopy. The latter is capable to deliver images of a much higher resolution and contrast than classical optical microscopes. The trick is basically done by having a laser scanning the probe point by point. The reflected light is recorded by a relatively simple device (although of extremely high sensitivity), a single cell sensor, called photomultiplier (Photomultiplier Tubes = PMT) and then the image is pixel by pixel assembled by a computer / software.
The two-photon laser scanning microscopes even further corroborated the breakthrough in biomedical imaging. The applicability of multi-photon excitation, the optical sectioning capability and the superior contrast of these instruments make them an ideal choice for fluorescence imaging of biological samples.
Gallery: Fluorescence Microscopy
The images in this gallery have been obtained with a confocal LSM (Laser Scanning Microscope) or by conventional fluorescent microscopy. In some cases, the usual "coding" of RGB (red, green, blue) for each channel has been changed to different colors.