Technology of storage and primary processing of agricultural products

1 LABORATORY WORK.
Topic: Laboratory equipment and acquaintance with them
Centrifuge Using a centrifuge tool, different systems are separated from each other by the centrifugal force on the rotors. Centrifuges are used for precipitation of solid particles, separation of emulsions, filtration, separation of kjori molecular compounds depending on their density. Depending on the type of work performed, specially designed centrifuges are used. Centrifuges are widely used in biological research. These include the separation of cell components by weight, and the deposition of proteins in solution. When the centrifuge rotor rotates rapidly, a centrifugal force is created, which is several times higher than the gravitational force. Because the density of the particles in the liquid is much higher than the density of the liquid, it separates from the center and falls into the sediment. 10 ml glass centrifuge tubes are used in table centrifuges. They are mounted on the rotor holding the tube test tube. It is not recommended to fill the test tubes to the top. Because when you stop the centrifuge, some of the liquid is spilled.
When working in a centrifuge, pay attention to the following:
1. Install the centrifuge on a flat surface.
2. When using a centrifuge, do not wait for a high speed. The speed is gradually increased.
3. The hood must be closed when using and stopping the centrifuge. '
4. The centrifuge tubes are brought to equilibrium in pairs. Equilibrium solutions are placed opposite each other.
5. If there is a vibration in the centrifuge, it is necessary to stop it immediately, identify the cause and eliminate it. Often the cause of tremor is due to the unequal weight of the two test tubes or the displacement of one of them.
Laboratory works on scales of biological laboratories least - mass (weight) with the help of gravity is able to detect. Therefore considered widespread scales laboratory equipment. Depending on the thematic weighing scales in different circumstances. Technical scales: measurement does not require a high thematic material, reagents, are used for medicinal preparations. Analytical scales: the need for high-precision measurement of the mass Bulgaar. Technical scales milligarmmli and grammlargacha measurement. Analytical scales 0,1-0,01 mg. a possibility of measurement. In addition, special scales are available. For example centrifuges balance the scales tubes.
When working with scales, pay attention to the following:
1. Scales should not be installed close to the batteries of heating systems, they should not be exposed to sunlight. The fact that the shoulders of the scales are not evenly touched by heat, can upset their balance.
2. The scales should be mounted on thick marble slabs, taking into account the vibrations of the table under the influence of lilac transport.
3. Whenever possible, scales should be installed in special rooms. If the scales are installed in general laboratories, strong acids cannot be stored around them. Because under their influence, the scales can corrode. 4. Weighing technical stones are used in technical scales. Analytical scales are special stones that are stored in holsters. www.ziyouz.com library 5. When working with technical and analytical scales belonging to the 1st class, their doors are closed to protect them from air currents. 
Before you start weighing, you need to make sure that the scales are set correctly according to the devil. Photometric instruments Photometry (absorbtsiometry) is a method of qualitative and quantitative analysis based on measuring the rate of absorption or scattering of light by substances. Absorption or extinction of light is directly proportional to the concentration of the light-absorbing substance, the thickness of the solution layer and the molar coefficient of extinction according to the Lambert-Buger-Berr law of photometry. A calibrated graph is created to identify any component in the biological material. The graph represents the relationship between the concentration (S) and the extinction (E) of a substance in solution. Photoelectrocalorimeters and spectrophotometers are used for photometric analysis. There are different models of photoelectrocolorimeters (FEK): KFK-2, FEK-M, FEK-56, FEK-60, KMFTs-2, MKMF-1 and others.
The above FECs are used to analyze the absorption of light by substances in painted solutions in the visible zones of the spectra. The operating instructions are given in the instrument manual.
Light microscopy and its structure Light microscopes are used to study the structure of biological objects. A light microscope shows objects at a magnification of 20-1500 times and more. The most important part of the microscope, the optical part, consists of a viewing tube. It has an eyepiece at the top of the tube and a lens at the bottom. Sh tativ. The stand of the microscope consists of a straight or curved column, which can be burned backwards. The tripod includes parts for the revolver, cremalera, microvint, macrovent, table, diaphragm, handle, base and fall. Lens. One of the main parts of a microscope that shows objects as a cat is the objective. The drug on the table should not be crushed by the lens.