1. The surface of the grinder must be wiped clean before and after work every day. 2. The lubricant inside the grinder must be replaced every half month to ensure the normal use of the grinder. The specific operation is as follows: 3. Each time after adding lubricating oil, let the grinder spin and wipe clean the overflowing lubricating oil. Avoid grinding when...

Fluorescence microscope is the use of a high luminous efficiency point light source, by filtering the colour system to send a certain wavelength of light (such as ultraviolet light 3650 into or violet blue light 4200 into) as the excitation light, excite the specimen within the fluorescent material emits a variety of different colours of fluorescence, and then through the objective lens and eyepiece magnification for observation. This makes it easy to identify even faint fluorescence against a strong background and is highly sensitive. The basic construction of a fluorescence microscope is based on an ordinary light microscope with a number of accessories (e.g. fluorescent light source, excitation filter, two-colour beam splitter and blocking filter, etc.).

The fluorescent light source - generally using ultra-high-pressure mercury lamp (50-200W), which can emit a variety of wavelengths of light, but each fluorescent material has an excitation wavelength to produce the strongest fluorescence, so the need to add excitation filters (generally have ultraviolet, purple, blue and green excitation filters), so that only a certain wavelength of excitation light through the irradiation to the specimen The excitation filter (usually available in UV, violet, blue and green) is used so that only a certain wavelength of excitation light is transmitted to the specimen and all other light is absorbed. Each substance emits visible fluorescence of a longer wavelength than that of the irradiated light for a very short period of time after being irradiated by the excitation light. The fluorescence is specific and generally weaker than the excitation light. In order to observe the specific fluorescence, a blocking (or pressed) filter is added behind the objective. It serves two purposes: firstly, it absorbs and blocks the excitation light from entering the eyepiece to avoid disturbing the fluorescence and damaging the eyes, and secondly, it selects and allows the specific fluorescence to pass through, showing the specific fluorescence colour. Both filters must be selected for use in conjunction with each other. There are two types of fluorescence microscopes in terms of their optical path.

1. Transmissive fluorescence microscopes:

The source of excitation is a light source that passes through the specimen material to excite fluorescence. A dark-field collector is commonly used, but a common collector can also be used, and the reflector is adjusted to divert and bypass the excitation light onto the specimen. This is the older type of fluorescence microscope. Its advantage is that the fluorescence is strong at low magnification, but its disadvantage is that the fluorescence decreases with increasing magnification. So it is better for observing larger specimen material.

2. Falling fluorescence microscope

This is a new type of fluorescence microscope developed in recent times, different from the above is the excitation light from the objective lens downward to the surface of the specimen, that is, using the same objective lens as an illumination concentrator and collect fluorescence objective lens. The light path requires the addition of a bichromatic beam splitter, which is at an angle of 45 to the light uranium. The excitation light is reflected into the objective and gathered on the sample, the fluorescence generated by the sample and the excitation light reflected from the surface of the objective lens and the surface of the coverslip enter the objective at the same time, and return to the bichromatic beam splitter, so that the excitation light and fluorescence are separated, and the residual excitation light is then absorbed by the blocking filter. The residual excitation light is then absorbed by the blocking filter. If different excitation filter/dual beam separator/blocker filter combination inserts are used, different fluorescence reaction products can be satisfied. The advantages of this type of fluorescence microscope are uniform illumination of the field of view, clear imaging, and the greater the magnification the stronger the fluorescence.

(B) fluorescence microscope use method

1. Turn on the lamp source, the ultra-high pressure mercury lamp should be preheated for a few minutes to reach the brightest point.

2. Transmission fluorescence microscope need to install the required excitation filter between the light source and the concentrator, and the corresponding blocking filter behind the objective lens. Falling fluorescence microscopes require the insertion of the required excitation filter/dual beam splitter/blocking filter in the slot of the optical path.

3. Observe with a low magnification microscope, adjusting the centre of the light source to the centre of the entire illuminated spot according to the adjustment devices of the different models of fluorescence microscopes.

4. Place the specimen film and focus it for observation. Use should be noted: the end of the installed filter do not use the eye to directly observe, so as not to cause eye damage; with the oil mirror to observe the specimen, must use the special oil mirror without fluorescence; high-pressure mercury lamp off can not be immediately re-opened, need to be after 5 minutes to start again, otherwise it will be unstable, affecting the life of the mercury lamp.

(iii) Observation of cells stained with o.01% maiden orange fluorescent dye under a fluorescent microscope with a blue-violet light filter on a demonstration table; the nucleus and cytoplasm are excited to produce two different colours of fluorescence (dark green and orange-red).