TECHNIQUES AND TOOLS IN BIOLOGICAL STUDIES

TECHNIQUES AND TOOLS IN BIOLOGICAL STUDIES:---------

Biological studies concerning cellular, biochemical,  physiological, genetical, environmental aspects etc. Require skillful techniques minute observation and analytical ability. 

          Biological studies mainly concerned with cells and cell constituents. The techniques in cell biology include microscopy, staining, cell fractionation, tissue culture, biochemical analysis, biophysical test etc. Any study involving cellular aspect must take the help of suitable microscope to investigate the cellular composition. Cells are generally transparent and therefore the cells and cell contains or not properly resolved unless the cells are suitably stained. Varied types of stains and staining techniques are available today. Open cells are properly fixed using fixing techniques before staining. What study of cellular arrangement aur tissue composition it may be necessary to cut him section of the plant or animal body before staining. In doing all this cells are killed. Methods are available by which living cells can also be observed under microscope,  particularly in phase Bhagwat contrast microscope, interference microscope etc. 

                                                 Staining distinguishes type of cells, type of cell components and type of organelles. The ability to distinguish depends upon the ability of the different parts to take up specific dye. A dye consists of a chromophoric group and an auxochromic group. The former is responsible for colouring and the letter in responsible for dyeing. Chromophores are some atomic groups of colour. The intensity of colour depending upon the number of such groups. Chromophores  alone cannot import Dye because it must be accompanied by auxochromes which have the affinity choose and form salts with either acid or alkali to impart dye. Dyes again can be divided as acidic dye, basic dye or neutral dye. Difference substances and cell components accept difference stains according to the chemical nature of the dye as well as the chemical nature of the substance and the components. 

                   Stains  are very useful in cytological studies involving chromosomes, nucleus, DNA RNA and other cell organelles. 

                                                  For cytological staining, Bhagat video the cells are required to be killed without causing distortion of the components to be studied. This is called fixing. Various fixatives such as acetic acid, propionic acid, formaldehyde etc. Are used which cause coagulation of the constituents of the cell as well as produce desirable condition for holding the stain. Cells or tissues are often required sectioning. Smaller objects are embedded in paraffin block and sectioning is with microtome. Proper staining often cells or tissues need the dehydration using dehydrating chemicals. 

                            For what the study of cellular components it is often necessary to bring out the cell organelles. Cell fractionation is a device by which all organelles are brought out of the cell. This is done by homogenization and centrifugation. Grinding aur Sone bhai basin break the cell wall and cell membrane and release the contents which are then separated using centrifugation. Centrifugation separate the component according to density and size of the components. The separated organelles are studied using other technique viz, cytological biochemical biophysical etc. 

                                     Biological substance are composed of buried chemical compounds which need separation for the purpose of identification. These compounds are separated using chemical means chromatography, electrophoresis, dialysis etc which are then identified. 

                          Colorimetry and spectrophotometry are used for identification and estimation for biochemical substance without going for chemical test. These methods are reliable and quick but required skills and understanding. Autoradiography is a highly sophisticated device using isotopes of different types for tracing the biochemical path for movement of solvent minerals enzymes etc in the body. Isotopes help in tracing the biochemical path of respiration photosynthesis translocation of food in plants. 

                                In study involving microorganisms the organisms are required to the cultivated and preserved. For this purpose physical media are prepared and sterilized to kill all variable organism. Isolated microorganisms are preserved under suitable temperature and under sterilized condition for study. Suitable methods are used to avoid contamination during isolation and cultivation.