Auksin. Definition of the maintenance of hormones in a plant

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For quantitative definition auksina in any fabric of a plant this fabric ekstragirujut any solvent, and then put an extract on other fabric which quantitatively reacts on containing in it auksin. Usually this fabric place in dietilovyj an aether at temperature nearby 0°С and cautiously stir up during 2-4 ch. The received radio extract then concentrate to small volume and enter in agarovyj the block which place on one party sensitive to auksinu dekapitirovannogo body. usually for this purpose use a vagina of the first sheet, or to-leoptil, the oats grown up in the dark. Asymmetrically located auksin strengthens in an investigated plant growth only that fabric which is directly under it. Non-uniform growth of two parties koleoptilja leads to the bend formation which corner is directly proportional to quantity entered into the block auksina. Thus, for quantitative definition auksina in unknown body from it the extract which is put on sensitive to auksinu body prepares. The arisen bend is measured and compared to the bends caused by known quantities auksina in other series of experiences. The described method of use of response of an organism for measurement of quantity of the chemical compound containing in an extract, is called as the biotest.

The Biotests based on an induction of certain level of response, developing usually at plants under the influence of the given hormone, exist for all vegetative

Hormones. Now they are superseded gradually by chemical and physical methods mainly because though biotests and are simple performed by, they are subject to influence of variety of external factors. Common fault of biotests is, for example, that from a fabric together with hormones often ekstragirujutsja ingibirujushchie connections. such mix causes weaker rostovuju reaction, than that which could arise under the influence of the given quantity rostovogo a hormone in absence ingibitorov. As a result of data on the maintenance in a fabric of a defined hormone appear erroneous. The majority of modern methods is based on clearing of the hormones containing in the received extract, hromatograficheskimi by methods, such, as a chromatography on a paper, in thin layers silikagelja or on columns with balls from synthetic pitch. The most sensitive method is the gas chromatography. At its use flying derivative a hormone separates from impurity in the course of its passage with a gas current at the raised temperature through a column with a material which differently absorbs a hormone and impurity. Other modern method - a liquid chromatography at a high pressure. The solution of a hormone with impurity under pressure passes in this method through a column filled with a material with different absorbing ability in relation to a hormone and impurity. as in all these methods for passage of a hormone and impurity through a column different time is required, the hormone is cleared also it it is possible to define directly. Both in gas, and in a liquid chromatography under a high pressure the hormone can be found out and identified after clearing. The physical detector of this or that type carries out this operation at once after an exit of defined connections from a column. IUK, for example, it is possible to find out and quantitatively to define, measuring at certain length of a wave the fluorescence raised at an irradiation of a solution by ultra-violet beams with certain length of a wave. Gibberelliny identify by means of a mass spectrometer in which these connections arrive directly from a column gas hromatografa. The mass spectrometer - difficult arranged device - is used to split all molecules of investigated substance on set of molecular ions (ionisation spend by bombardment of substance by a bunch elektronov or other ways), which then are divided according to size of the relation of their weight to a charge. As registered sets of fragments (molecular ions) are characteristic for certain initial molecules, by means of this device it is possible to identify and quantitatively to define any hormone.