Question

why water is used as mounting material in studying cyclosis​

Answer 1

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To observe the cells in an onion peel, we prepare a slide by adding Glycerin as a mounting agent to the onion peel specimen. Glycerin prevents the drying up of specimen and also helps in getting a clear picture under the microscopic lens. Apart from that, Glycerin also protects the specimen from dust and damage along with preserving the cellular characteristics of the specimen as well as the quality of the stain. Most of these benefits are attributed to the chemical stability of Glycerin.

Answer 2

AIM 1. Demonstration of Staining and Mounting Methods

A. Staining is a technique used in microscopy to enhance contrast in a microscopic image.

Stains and dyes are frequently used to highlight structures in microbes for viewing, often with

the aid of different microscopes. Staining may be single or double.

1. Single Stain: Safranin or fast green is used to stain filaments of lagae, fungi, sections of

bryophytes, spores of pteridophytes, pollen grains of angiosperms etc. Aniline blue or safranin is

usually used for single staining methods.

Procedure: - Keep material in watch glass

- Few drops of stain are added to the water to another watch glass to dilute the stain.

- The diluted stain is added to the material.

- After the stain is taken up by sample, the extra stain is washed with water.

- Washing is repeated till the stain stops coming out.

- The stained material is now ready for mounting.

2. Combined Stain: In this technique, two or more stains are used. Generally contrasting colours

are used. The following combinations are commonly employed.

• Haematoxylin and Safranin

• Safranin and fast green

• Safranin and Aniline blue

• Safranin and Crystal violet

• Crystal violet and Erythrosine

Procedure: - The section is first stained with principle stain.

- Section is passed through a graded series of alcohol for degradation.

- Section is transferred to watch glass containing required amount of alcohol and water.

- Watch glass should be covered by larger watch glass to avoid alcohol evaporation.

- Now the counter stain is employed for few seconds.

- The section is transferred to absolute alcohol for 5-7 min for complete dehydration.

- Section is finally immersed in xylene. If dehydration is not complete, pure xylene

turns white or turbid.

- Now the section is ready for mounting.

B. Mounting is necessary for proper positioning of objects for clear view. Lactophenol, glycerin

and glycerine jelly are used for temporary mounting while Canada balsam is used for permanent

mounting.

Mounting Media: Following are some of the common media:  

Department of Botany, DAV College, Jalandhar (PB.)

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- Canada Balsam: It is resin obtained from conifer. It is most suited for permanent slide

preparation.

- Lactophenol: It is a mixture of equal parts of phenol crystals, lactic acids, glycerine and

distilled water.

- Glycerine: Pure glycerine diluted to 15-25% is widely used for semipermanent and temporary

preparations.

- Glycerine Jelly: Jelly is used for mounting. It is made up of gelatin.

Many other mounting media like cedar oil, balsam, venetiane, turpentine, synthetic resin

etc are also used.  Explanation: