A VERSATILE 2-PI-TILTING DEVICE FOR FLUORESCENCE MICROSCOPES

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.