Image contrast enhancement in confocal ultramicroscopy.

Ultramicroscopy allows for the 3D reconstruction of centimeter sized samples with a spatial resolution of several micrometers. Nevertheless, in poorly cleared or very large specimens the images may suffer from blurring and low contrast levels. To address these problems, ultramicroscopy was combined with the principle of confocal microscopy using a slowly rotating Nipkow disk. This configuration was tested by comparing images from mouse hippocampal neurons and mouse liver blood vessels recorded in confocal and conventional mode. It was found that confocality minimizes the background noise and considerably improves the signal-to-noise ratio when applied to ultramicroscopy.