A tilting device for biological specimens (rotation angle up to 2 pi),
especially fluorescence-lablelled cell nuclei, was developed. It cons
ists of a quartz glass capillary and a mounting adapter for the micros
cope stage. The applicability of the device was tested for several epi
fluorescence and confocal scanning laser fluorescence microscopes. The
axis of rotation is perpendicular to the optical axis of the microsco
pe. The capillary can be tilted around its axis at any desired angle o
r in equiangular steps. This can be done manually or by remote control
using a stepping motor. The three-dimensional (3-D) image-forming pro
perties of the capillary system were experimentally examined using an
inverse confocal scanning laser microscope. The results were compared
with measurements obtained from the same microscope with the standard
stage for plane slides with cover glasses. The measured point spread f
unction suggested that in spite of aberration effects, the optical arr
angement used allows a gain in the 3-D resolution by tilting the objec
t. A low-cost, fully automated 3-D imaging system was built on the bas
is of a conventional epifluorescence microscope with a cooled black-an
d-white CCD camera. The system was operated by a personal computer. Th
e online visualization ('movie') of rotating objects indicates the fea
sibility of the system.