Axioskop 40 fl upright microscope

Embryos with intact embryonic vesicles were mechanically removed from their mother spheroid up to 3 h before the onset of inversion. For this purpose, 5 ml of a P. californica culture were passed through a syringe needle with a diameter of 0.4 mm. High-resolution in vivo stereo light microscopy was performed using a motorized and automated Leica MZ16A stereomicroscope (Leica Microsystems, Wetzlar, Germany) with fully apochromatic optics and a transmitted light illuminator with cold light sources [38 (link)]. In this system, a resolution of up to 840 Lp mm-1 (=0.6 μm) was obtained. For higher magnifications, an Axioskop 40 FL upright microscope (Carl Zeiss, Oberkochen, Germany) equipped with Achroplan, Fluar and Plan-Neofluar objectives of up to 100× magnification was used. A digital PowerShot S50 camera (Canon, Tokyo, Japan) with a1/1.8” charge-coupled device sensor was used for photographic documentation.

Toluidine blue-stained sections (approximately 2 μm in thickness) of embryos were analyzed with an Axioskop 40 FL upright microscope (Carl Zeiss) using oil immersion objectives. The total magnification for light microscopy was up to 1000×. Heavy metal-stained sections (approximately 80 nm) were examined with a Hitachi H-500 transmission electron microscope (Hitachi, Tokyo, Japan) operated at 75 kV and with a Philips CM-100 transmission electron microscopy (Philips, Eindhoven, Netherlands) operated at 80 kV. The total magnification for transmission electron microscopy ranged from 3600 × to 40,000 ×.