Princip og Konstruktion af Fluorescens Mikroskop
Fluorescence microscope uses a high luminous efficiency point light source, which emits a certain wavelength of light (such as ultraviolet light 3650 in or violet blue light 4200 in) through a color filtering system as excitation light, and excites the fluorescent substances in the sample to emit various colors of fluorescence. After that, it is observed through magnification of the objective and eyepiece. In this way, even with weak fluorescence, it is easily recognizable and highly sensitive under strong contrasting backgrounds, mainly used for studying cell structure and function, as well as chemical composition. The basic structure of a fluorescence microscope is composed of an ordinary optical microscope and some accessories (such as a fluorescent light source, excitation filter, bichromatic beam separator, and blocking filter, etc.). Fluorescent light sources - usually use ultra-high pressure mercury lamps (50-200W), which can emit light of various wavelengths. However, each fluorescent substance has an excitation light wavelength that produces the strongest fluorescence, so excitation filters (usually ultraviolet, purple, blue, and green excitation filters) need to be added to allow only a certain wavelength of excitation light to pass through and illuminate the specimen, while absorbing all other light. After being irradiated by excited light, each substance emits visible fluorescence with a longer wavelength than the irradiation in a very short period of time. Fluorescence has specificity and is generally weaker than excitation light. In order to observe specific fluorescence, a blocking (or suppressing) filter needs to be added behind the objective lens. It has two functions: firstly, it absorbs and blocks excitation light from entering the eyepiece to avoid disturbing fluorescence and damaging the eyes; secondly, it selects and allows specific fluorescence to pass through, displaying a specific fluorescence color. Both types of filters must be selected for use together.
Der er to typer af fluorescens mikroskoper baseret på deres optiske vej% 3a
1. Transmission fluorescens mikroskop: Den excitation lys kilde er transmitteret gennem prøven materiale gennem a kondensator til excitere fluorescens. Almindeligt brugt mørkt felt lys samlere, eller almindeligt lys samlere, kan bruges til justere reflektoren til konverter excitation lys og side lys på prøven. Dette er a relativt gammeldags fluorescens mikroskop. Dens fordel er at den fluorescens er er stærk ved lav forstørrelse, mens dens ulempe er erden den fluorescens svækker som den forstørrelse stiger. Derfor, it er bedre til iagttagelse større prøve materialer.
2. Falling beam fluorescence microscope This is a new type of fluorescence microscope developed in modern times. Unlike the previous one, the excitation light falls down from the objective lens to the surface of the specimen, using the same objective lens as the illumination condenser and the objective lens for collecting fluorescence. A dual color beam separator needs to be added to the optical path, which is at a 45 degree angle to the light uranium. The excitation light is reflected into the objective lens and concentrated on the sample. The fluorescence generated by the sample, as well as the excitation light reflected from the surface of the objective lens and cover glass, enter the objective lens simultaneously and return to the dichroic beam separator, separating the excitation and fluorescence. The residual excitation is then absorbed by the blocking filter. If different excitation filters/dual color beam separators/blocking filter combinations are used, they can meet the needs of different fluorescent reaction products. The advantage of this fluorescent microscope is that the field of vision illumination is uniform, the imaging is clear, and the larger the magnification, the stronger the fluorescence.
