Simple staining of bacteria and Terran's staining

(i) Experimental purpose:
to learn simple staining methods of bacteria and Terranean staining methods.
(ii) Experimental principle:
dyes used for biological dyeing mainly have alkaline dyes, acidic dyes and neutral dyes three categories. The ions of alkaline dyes are positively charged and can bind to negatively charged substances. Because of the low electrical points such as bacteria
green
, when it is often negatively charged when it grows in neutral, alkaline or weakly acidic solutions, it is usually colored with alkaline dyes (e.g. melancholy, crystalline purple, alkaline redness, or peacock green). The ions of acidic dyes are negatively charged and can be combined with positively charged substances. When bacteria break down sugar-producing acids to cause
culture
-based pH to decrease, the positive charge on the bacteria increases, making them susceptible to coloring by acidic dyes such as Irma, acidic redness, or Congolese red. Neutral dyes are the combination of the first two, also known as composite dyes, such as Yihong Mei blue, Yihong Tianqing and so on.
simple dyeing method is to color bacteria with only one dye to show their form, simple dyeing can not distinguish the structure of bacterial cells.
Gram was founded in 1884 by C. Gram,
Danish
of Pathology. Globe's staining method, which distinguishes all bacteria into the two main categories of Terrain-positive bacteria (G-plus) and Gloran-negative bacteria (G-), is the most commonly used method of identifying staining in bacteriology.
the dyeing method so that bacteria can be divided into G-plus bacteria and G-bacteria, by the two types of bacteria cell wall structure and composition of different decisions. G-bacteria cell walls contain more easily dissolved lipids by ethanol, and peptide polysaccharide layer is thin, low cross-linking, so the use of ethanol or acetone decolorization dissolved lipids, increased cell wall permeability, so that the initial staining of crystalline purple and iodine complex easily seepage, the result of bacteria are decolorized, and then red after red re-dyeing. The peptide polysaccharide layer in the cell wall of G-plus bacteria is thick and cross-linked, the lipid content is small, but after the decolorizer treatment, the aperture of the peptide polysaccharide layer is reduced, the permeability is reduced, so the bacteria still retain the color at the time of initial dyeing.
(iii) Experimental equipment
1, living materials: culture 12-16h of Bacillus thuringiensis or Bacillus subtilis, culture 24-hour E. coli (Es) cherichia coli)
2, dyeing fluid and
reagents
: crystalline purple (with two, one), three), Lugo's iodine (with two, one), 4), 95% alcohol, red (with two , (i), 5), red (with two (i), 2), xylene, balsamic
3, equipment: waste tank,
wash bottle
, slide, vaccination cup, alcohol lamp, mirror paper,
Microscope
(iv) Experimental method:
1, simple dyeing:
(1) smear: take a piece of clean slide, add a drop of distilled water to the left and right of the slide, take the bacterial smear according to the sterile operation method, On the left is Suyun Jinli, on the right is E. coli, to make a thick bacteria solution. Then take a clean slide piece will be just made of Suyun Jinli bacteria thick bacteria liquid pick 2-3 ring on the left to make a thin coating surface, E. coli thick bacteria liquid to take 2-3 rings on the right to make a thin coating. Can also be made directly on the slide thin coating surface, pay attention not too much bacteria.
(2) dry: Let the smears dry naturally or over the flame of the alcohol lamp.