Microscopes

Proper setup of a stereo-dissecting-type microscope is important for good microsurgery. In addition to to good posture, eyepiece height, and working height of the bench, it is very important to adjust the eyepieces according to the manufactuer's instructions, such that both eyes focus at the same level and have stereoptic vision. We work on a large, flat, cooled surface, rather than on a raised stage. We buy the microscope with a boom stand or without a stand, and mount the microscope to a large cooling plate, of dimensions 40 x 80 cm. The cooling plate is made by milling a continuous, 2-cm-wide channel in a sheet of Plexiglas of this size, about a centimeter thick, beginning at the back right hand corner, coming forward, turning towards the back again, and so on, in a continuous, sinuous pattern, staying about 3 cm from the edge, and ending at the back left. This channeled plate is glued to a second Plexiglas plate. Finally the pair of plates are glued and screwed, with machine screws, to the aluminum plate. The screw heads are recessed into the bottom Plexiglas plate, forming a smooth surface, and are screwed into tapped holes on the underside of an aluminum plate. The aluminum plate is then drilled and tapped for a water inlet and outlet. These are located over the ends of the channels in the Plexiglas at the back right and left of the plate in order to maximize water flow and to be out of the way. The inlet is made smaller (3/8 in.) than the outlet (1/2 in.) to reduce buildup of internal pressure. Water is circulated through the plate from a large water bath/chiller, and adjusted to 16-18°C. A boom stereoscope is swung out over the plate, or a pillar matching the diameter of that required for the stereoscope is mounted on the aluminum plate, using a 3/8 in. machine screw-tapped into the base of the pillar and into the top of the plate. Illumination is by fiber optic illuminator, which is cool and does not heat the embryos.

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