Structural Components and Related Functions of Fluorescence Microscope
Light source
More than 200W of ultra-high-pressure mercury lamp as a light source, it is made of quartz glass, the middle of the spherical, filled with a certain amount of mercury, work by the two electrodes between the discharge, caused by the evaporation of mercury, the ball of air pressure rises rapidly, when the mercury completely evaporated, up to 50 ~ 70 standard atmospheric pressure, this process generally takes about 5 ~ 15min. ultra-high-pressure mercury lamp luminescence is the electrode discharge so that mercury molecules Continuously dissociate and reduce the results of the process of emission of light quanta. It emits strong ultraviolet and blue-violet light, which is sufficient to excite all kinds of fluorescent substances, therefore, it is commonly used for fluorescence microscopy.
UHV lamps also emit large amounts of heat. Therefore, the lamp room must have good heat dissipation conditions, the working environment temperature should not be too high.
New ultra-high-pressure mercury lamp in the use of the initial period does not require high voltage can be ignited, after using some time, it is necessary to start the high-voltage (about 15,000V), after starting, maintaining the working voltage is generally 50 ~ 60V, the working current of about 4A or so. 200W ultra-high-pressure mercury lamps in the case of each use of the average life of 2h is about 200h, the shorter the start of a work, the shorter the life, such as open The shorter the working time, the shorter the life, such as open only 20min, the life is reduced by 50%. Therefore, use to minimise the number of starts. Bulb in the process of use, its light efficiency is gradually reduced. Wait for the lamp to cool down before restarting it after it is extinguished. The bulb should not be turned off immediately after ignition to avoid damage to the electrode due to incomplete evaporation of mercury, generally need to wait for 15 min. due to the high pressure of ultrahigh-pressure mercury lamps, ultraviolet rays are strong, so the bulb must be placed in the lamp room before ignition to avoid injury to the eyes and explosion.
Colour filter system
The colour filtration system is an important part of the fluorescence microscope, consisting of the excitation filter plate and the suppression filter plate. Filter plate model, the name of each manufacturer is often not uniform. Filter plate is generally named after the basic tone, the front letter represents the tone, the back letter represents the glass, the number represents the characteristics of the model. Such as German products (Schott) BG12, is a kind of blue glass, B is the first letter of the blue, G is the first letter of the glass; China's product name has been unified with the pinyin alphabet, such as the equivalent of BG12 blue filter plate named QB24, Q is the first letter of the pinyin of cyan (blue), B is the first letter of the pinyin of glass. However, some filter panels can also be named as the light transmission cut-off filter length, such as K530, which means that the suppression of the filter length of 530nm below the light and through the light above 530nm. There are manufacturers of filter plate completely named after the number, such as the United States Corning plant NO: 5-58, which is equivalent to BG12.
Excitation filter plate According to the light source and the characteristics of the fluorochrome, the following three types of excitation filter plate can be used to provide a certain wavelength range of excitation light.
UV excitation filter plate: this filter plate can make the ultraviolet light below 400nm through, blocking the visible light above 400nm through. Commonly used models are UG-1 or UG-5, plus a BG-38 to remove the red tail.
UV blue excitation filter plate: this filter plate can make the light within the range of 300 ~ 450nm through. Commonly used models are ZB-2 or ZB-3, plus BG-38.
Violet-blue light excitation filter plate: It allows light in the range of 350 to 490nm to pass through. The commonly used model is QB24 (BG12).
