The procedure is as follows: The absorbance rate was monitored at nm until it reached a nominal zero value. When the smears are treated with these dyes and washed with acids and alcohols they are not decolorised and retain the stain of the dye.
The main source of error in lab came from not correctly measuring out the substances, resulting in a very askew time and rate of reaction. This is the most commonly used method for differential staining of bacteria.
Store the solution in amber coloured glass bottles. Counterstain methylene blue or malachite green. The capsular zone is seen as a clear space between the refractile portion and dark background of the dye.
During this time compounds are formed in the cytoplasm of the bacterial cell, which are retained by some bacterial species during deceleration with alcohol. The average value of k calculated from the three trials was found to be about 2.
This process is very rapid and completes in seconds. When I2 was first added to the cuvette, it was dark red in color. It is a very simple and useful method which was first used in by Gram and till now it has not lost its practical significance.
During steaming care must be taken that the stain should not evaporate to dryness. Basic fuchsine 10 gm. Distilled water up to ml. Dissolve basic fuchsine in alcohol and allow to stand for 24 hours. Distilled water up to I00 mi.
The ordinary staining dyes do not penetrate the spore walls therefore a specialised technique is used for staining the spores which is described as follows: Go on washing the slide till no colour comes out. If heat fixation is contraindicated then dip the film in alcohol for fixation.
Bacteria is seen as a highly refractile outline against dark background of the dye. For this purpose other techniques are used which are described under respective categories. Add sufficient water to make up the volume to ml.
Continue steaming for about ten minutes. To conduct this experiment, the groups placed 1. Spore producing bacteria like bacillus anthracia, the causative agent of anthrax and Clostridium tetani, the causative agent of tetanus are identified by this technique.
Staining contrast will be seen between the organism and the capsule. Acid fast staining technique was first developed by Paul Ehrlich in for differential staining of microorganisms. Those bacteria which cannot be decolorised with alcohol or acetone and retain violet colour are known as gram positive bacteria and those bacteria which are decolorised by alcohol or acetone and stains red due to fuchsine solution are known as gram negative bacteria.
The starting concentrations were varied according to the experiment design in order to calculate the rate law exponents. The rate law does not include [I2] because I2 does not impact the rate of chemical reaction under the conditions selected.
In this method dyes like malachite green and methylene blue are used. Dissolve potassium iodide in water and to this dissolve iodine.
Such bacteria which are not decolorised are known as acid fast bacteria but the bacteria which lose the stain and get decolorised are known as non-acid fast bacteria. All bacteria stained by Gram method can be grouped according to colour as gram positive and gram negative.
The Ziehl-Neelson method is used for differentiating acid fast bacteria mycobacterium tuberculosis, a causative organism of tuberculosis and mycobacterium leprae, a causative organism of leprosy which stain with difficulty due to their structure and hence steaming concentrated carbol fuchsine is used to stain them.
The slide will appear pink coloured and rod shaped tubercle bacilli will be seen scattered in the film. Dissolve in distilled water. Allow the stain to remain in contact for 5 minutes, heat being applied at intervals to keep the stain hot but the stain must not be allowed to evaporate to dryness.
At this point, the spectrophotometer displayed that at nm, zero light was being absorbed in the solution.
The spores are stained green in colour and vegetative portion of the cell is stained red or pink in colour. The acid fast microorganisms are stained pink or bright red whereas the background tissues, cells and other non-acid fast bacilli are stained blue or green.Experiment Synthesis of Dibenzalacetone by the Aldol condensation Introduction: The Aldol condensation reaction, under basic conditions, involves the nucleophilic addition of an enolate ion to another carbonyl group.
The benefit of this lab was to acquaint oneself with the fundamentals of the Aldol Condensation reaction by demonstrating the synthesis of dibenzalacetone (trans, trans-1,5-Diphenyl-1,4-pentadienone) through the aldol condensation of acetone with benzaldehyde.5/5(8).
It was found that both Acetone and H + have a direct effect on the reaction rate of I 2. The rate law for acetone iodination is rate= k [Acetone][H + ].
The average value of k calculated from the three trials was found to be about e-5 M -1 s These methods are also used to study the morphological characteristics of bacterial cells, spores and capsules. ADVERTISEMENTS: The various stains used for differential staining are Gram, crystal violet, methyl violet, fuchsine and Ziehl-Neelsen.
Acetone can also be used for medical and cosmetic uses, such as applying acetone with alcohol for acne treatments to peel dry skin.
It can also remove residues from glass and porcelain and it can also remove super glue from the skin. Glue out of Cigarette Filter and Acetone Essay. A+. Pages Words This is just a sample. To get a unique essay. We will write a custom essay sample on Glue out of Cigarette Filter and Acetone specifically for you for only $ $/page.
school discipline, family background and school location”. Another study was the one.Download