Introduction to Darkfield Microscopy
In ordinary microscopes, the illuminating light passes through the sample from the bottom of the sample through the condenser and then enters the objective lens. It is suitable for observing samples that are transparent to light. If the oblique light is used to irradiate the object, the direct light cannot directly enter the human lens, and only the reflected light emitted by the specimen after oblique illumination can enter the objective lens, so that the bright object image in the dark field can be seen under the microscope. Subtle parts of the specimen, such as the movement of bacterial flagella and Treponema pallidum and Treponema fensenii, can be observed using dark-field microscopy.
The difference between the condenser: the difference between the dark field microscope and the general bright field microscope is that the condenser of the two is different. The dark field condenser can prevent the light from directly irradiating the specimen, and make the light obliquely shine on the specimen. The commonly used dark field concentrators are parabolic concentrator, cardioid concentrator and concentric spherical concentrator.
Focusing range: The vertical movement of the stage is guided by the roller (rack-pinion) mechanism, and the coarse and fine coaxial knobs are used.
The coarse adjustment stroke is 36.8mm per circle, the total stroke is 25mm, and the fine adjustment stroke is 0.2mm per circle. Some microscopes have coarse stops and tension adjustment rings
