Electronic microscopy

For research of structure of membranes the electronic microscope which permitting limit is defined by length of a wave of de Broil for moving with high speed of electron is used: .

Where h - Planck's constant; m - weight of electron; - speed of electron. The permitting limit of

an electronic microscope can be . Tungsten, osmium and some other chemical elements well absorb and disperses electrons. The membrane becomes covered by these substances for reception precise electron gram of the cells.

For research of membranes methods of freezing-breaking off and freezing-etchings are used. Preparations are quickly frozen, without damaging influences, as at reception of thin cuts. Preparation of a preparation includes a number of operations. After freezing the sample. representing suspension of cells, breaks away by means of a knife at low temperature (-100⁰ С) in deep vacuum. At breaking off the cut which is passing through the sample is formed. If the plane of a cut passes through a membrane, it breaks up on median area and is split on two half. The internal area of a membrane is naked on the formed planes of cut.

If necessary the sample is exposed to etching, sublimation of an ice is spent in vacuum. It allows to see superficial structures of cellular membranes better. After that the sample from the naked surface is received. This sample is studied by a method of electronic microscopy. First the sample becomes covered by platinum under a corner nearby 45⁰ to reveal topological characteristics of a preparation. Then the sample becomes stronger, putting on it a layer of carbon. After that the preparation is thaw, the sample emerges.

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