the Cage of a green plant. Approaches to cage research

you are: the Cage of a green plant

Biologists study cages various methods. On the first place among them it is natural to name direct visual supervision, however the largest cages give in to such supervision only. For smaller the increase which can be reached by means of a simple magnifier (approximately 10Х) or the usual microscope having system of lenses (to 1000Х) is required. In a light microscope the live three-dimensional cage is represented sometimes very difficult, changeable and disorder formation. Aspiring to reception of more simple and stable picture, biologists have learnt to kill cages and to keep them by immersing in any clamp, for example in formaldehyde. The killed and fixed cages wash, dehydrate carrying out through spirit, fill in in any dense environment, for example in paraffin or plastic, and then prepare from them thin cuts by means of the razor or microvolume. Under favorable conditions the microvolume gives the chance to receive cuts in the thickness from 1 to 10 microns. To reveal separate cellular structures, these thin cuts place consistently in the various dyes different from each other by solubility and a molecular charge and thereof adsorbed different cellular structures. at enough careful work and corresponding skill it is possible to receive such way a picture in which separate cellular structures will be painted differently, we will tell a nuclear material - in pink colour, cytoplasmatic structures - in green or violet with different shades, and cellular walls are not painted in general or painted in any colour. Almost all from this that we know now about a cage, scientists have found out in such a way, using various methods of fixing of a material, its pouring on Wednesday, preparations of cuts and colouring.

Still bolshee the increase (to 1 000 000 X) provides an electronic microscope. In it instead of a light bunch the bunch elektronov is used that gives the chance to receive bolshee the permission as resolution inversely proportional to length of a wave of used radiation, and lengths of waves de Brojlja elektronov are very small in comparison with lengths of waves of a visible range of a spectrum. A theoretical limit of the permission in an electronic microscope will not reach yet. It speaks that electric ' noise ' in the magnetic lenses focusing a bunch elektronov, does the image astable. However the recent improvements calculated on lowering this ' noise ' (for example, strong cooling of lenses), allow to hope that eventually in an electronic microscope it will be possible to reach still bolshego permissions.

For electronic microscopy from the cages filled in in plastic prepare thin cuts by means of diamond or glass knifes. Then cuts process such reagents, as chetyrehokis osmium; these reagents selectively join various cellular structures and do them in a different measure opaque for elektronov. After that on a photographic plate or on the fluorescent screen study details of the received picture. Structures in electronic microphotos are not painted - they black, white or grey; to receive colour images we for the present have not learnt.

One more way of reception of the information on cages is connected with chemical research allocated cellular organell. If cautiously to pound cellular weight in the corresponding environment then cellular organell it is possible to allocate a part in intaktnom a kind. Organelly, having various density, divide tsentrifugirovaniem at constantly increasing number of turns (fig. 2.1). For example, such heavy particles as kernels and hloroplasta, are besieged at rather small speeds corresponding to centrifugal forces, in 1000-3000 times exceeding force of terrestrial gravitation (1000-3000 g); mitohondrii pass in a deposit approximately at 10 000 g, ribosomes - approximately at 30 000 g, and for smaller particles and for large molecules it can be demanded and in 100 times a great speed tsentrifugirovanija. Differential tsentrifugirovanie along with other methods (step filtering, physical absorption and eljutsiej or division on size of an electric charge) allows to receive in enough separate kinds cellular organell or their fragments. Received hloroplasta, mitohondrii, ribosomes, membranes and other fragments are used then for the experiments, which purpose consists in defining the chemical nature and biochemical activity of each of these allocated fractions.