Phase Contrast Microscope Alignment - أطلس مختبرات العرب

Before attempting to align a microscope for phase contrast observation, examine the instrument carefully to ensure that all objectives contain phase plates and are firmly seated in the nosepiece. The objectives should also be sequentially ordered in their arrangement on the nosepiece, from lower to higher magnification, in order to minimize changeover frequency between one condenser annulus and another. Often the 10x and 20x objectives share a common condenser annulus, as do the 40x and 60x objectives. Highly corrected objectives, such as apochromats designed for oil immersion, often have similar numerical apertures and utilize the same condenser annulus over a wider range of magnification (40x to 100x). Low power phase contrast (4x and 5x) usually requires a swing-lens condenser and a specialized condenser annulus