The clearing agents merely improved the refractive index of the tissue. It should be miscible with Alcohol to promote rapid removal of the dehydrating agent from the tissue. The decalcifying agent should have a volume of 30—50 times that of the tissue and occasional agitation may be required to expedite this process.
Clearing agents are used to make the slides easier to read, by making the tissue transparent, or clear. Clearing is a step that occurs during tissue processing, after water has been removed from a tissue. Xylene is used because wax is not soluble in water.
Xylene C8H10 is a colorless, flammable liquid with a sweet odor. Exposure to xylene can irritate the eyes, nose, skin, and throat. Short-term exposure of people to high levels of xylene can cause irritation of the skin, eyes, nose, and throat; difficulty in breathing; impaired function of the lungs; delayed response to a visual stimulus; impaired memory; stomach discomfort; and possible changes in the liver and kidneys.
Carrot oil, Olive oil, Pine oil, Rose oil, are not only bio friendly and economical but can also be used as clearing agent instead of xylene. Cobalt chloride paper may be purchased or made. See this standard procedure for making your own cobalt chloride paper. Potassium dichromate VI paper may be made in the prep room. See Standard procedure: Preparing and using potassium dichromate VI indicator papers. Place the beaker and contents in a large bowl of water and leave for some time to dilute any remaining acid.
Small quantities can be broken up with a gloved hand and flushed down the sink. Larger amounts can be placed inside several sealed plastic bags before putting it in the waste bin. Procedure Weigh about 50 g of sucrose ordinary table sugar into the cm 3 beaker. Stand the beaker on a large watch glass or white tile in a fume cupboard. Clamp the beaker. The sugar will turn yellow, then brown. After about a minute, the sugar will start to blacken.
A spongy mass of carbon will begin to rise up the beaker, and steam will be evolved. The carbon will eventually rise to two or three times the height of the beaker. The steam can be tested with cobalt chloride paper. This will turn from blue to pink. Active Oldest Votes. Improve this answer. Karsten Theis Farooq M. Farooq Once one know what it is spoken about, it is more than acceptable to say that reaction between sulphuric acid and, eg, a sugar, is a dehydratation one.
Of course, it has nothing to do with a real extraction or with drying. Indeed water isn't there, but it is a dehydratation reaction.
Beside this, plus 1 for fixing the thread. Is possible this exothermic nature is just more commonly known for H2SO4, as it is more common acid form? In a closed dessicator, for example, the acid will be separate from the substance to be dried. All that matters here is that any water vapour in the vessel will be rapidly absorbed by the acid as that is highly favoured by the thermodynamics of water mixing with the acid.
And the low vapour pressure of the acid won't contaminate the substance. The same must be true for nitrogen dioxide. There is indeed something special about sulfuric acid and water combination.
Acids of P V are not particularly strong dehydration agens. Show 2 more comments. Learn from an expert tutor. Book a free class! Solution: Sulphuric acid removes water from substances and for drying gases, it acts as a drying agent. Fused calcium chloride is a desiccating agent as it dries the substance. Set your child up for success with Lido, book a class today! Maths Class 6 Class 7 Class 8.
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