CHAPTER V
REAGENTS
Little attention is given in the present work to micro-chemical reactions for the reason that their value has been much overrated in the past. A few reagents will be found useful, however, and these few are given, as well as their special use. They are as follows:
LIST OF REAGENTS
• Distilled Water is used in the alcohol, glycerine, and water mixture as a general mounting medium. It is used when warm as a test for inulin and it is used in preparing various reagents.
Glycerine is used in preparing the alcohol, glycerine, and water mixture, in testing for aleurone grains, and as a temporary mounting medium.
Alcohol is used in preparing the alcohol, glycerine, and water mixture, in testing for volatile oils.
Acetic Acid. Both dilute and strong solutions are used in testing for aleurone grains, cystoliths, and crystals of calcium oxalate.
Hydrochloric Acid is used in connection with phloroglucin as a test for lignin and as a test for calcium oxalate.
Ferric Chloride Solution is used as a test for tannin.
Sulphuric Acid is used as a test for calcium oxalate.
Tincture Alkana is used when freshly prepared by macerating the granulated root with alcohol and filtering, as a test for resin.
Sodium Hydroxide. A five per cent solution is used as a test for suberin and as a clearing agent.
Copper Ammonia is used as a test for cellulose.
Ammonical Solution of Potash is used as a test for fixed oils. The solution is a mixture of equal parts of a saturated solution of potassium hydroxide and stronger ammonia.
Oil of Cloves is used as a clearing fluid for sections preparatory to mounting in Canada balsam.
Canada Balsam is used as a permanent mounting medium for dehydrated specimens, and as a cement for ringing slides.
ParaSin is used for general embedding and infiltrating.
Lugol's Solution is used as a test for starch and for aleurone grains and proteid matters.
Formic Acid. A two per cent solution is used as a test for fixed oils.
Alcohol, Glycerine, and Water Mixture is used as a temporary mounting medium and as a qualitative test for fixed oils.
Chlorzinc Iodide is used as a test for suberin, lignin, cellulose, and starch.
Analine Chloride is used as a test for lignified cell walls of bast fibres and of stone cells.
Phloroglucin. A one per cent alcoholic solution is used in connection with hydrochloric acid as a test for lignin.
Heematoxylin-Delifields is used as a test for cellulose.
REAGENT SET
Each worker should be provided with a set of reagent bottles (Fig. 38). Such a set may be selected according to the taste of the individual, but experience has shown that a 30C.C. bottle with a ground-in pipette and a rubber bulb is preferable to other types. In such forms the pipettes are readily cleaned, and the rubber bulbs can be replaced when they become old and brittle.
The entire set should be protected from dust by keeping it in a case, the cover of which should be closed when the set is not in use.
MEASURING CYLINDER
In order accurately to measure micro-chemical reagents, it is necessary to have a standard 50 c.c. cylinder (Fig. 39) graduated to c.c.'s. Such a cylinder should form a part of the reagent set.
STAINING DISHES
There is a great variety of staining dishes (Fig. 40), but for general histological work a glass staining dish with grooves for holding six or more slides and a glass cover is most desirable.
<Callout type="tip" title="Pro Technique">Always keep your reagent set in a dust-free case to maintain accuracy.</Callout>
<Callout type="warning" title="Safety Hazard">Be cautious when handling strong acids like hydrochloric acid and sulphuric acid, as they can cause burns.</Callout>
<Callout type="important" title="Critical Rule">Always use a 50 c.c. cylinder for measuring reagents to ensure accuracy in your tests.</Callout>
<Callout type="risk" title="Risk of Failure">Incorrectly prepared reagents can lead to misidentification and failure in survival situations.</Callout>
Key Takeaways
- Distilled water, glycerine, alcohol, acetic acid, hydrochloric acid, and other reagents are essential for histological testing.
- A set of reagent bottles with a ground-in pipette and rubber bulb is recommended for accuracy and ease of use.
- Proper storage in a dust-free case is crucial to maintain the effectiveness of reagents.
Practical Tips
- Always keep your reagent set organized and accessible, ensuring you have all necessary chemicals on hand during survival situations.
- Use a standard 50 c.c. cylinder for measuring reagents to ensure accurate results in your tests.
- Regularly check the condition of your rubber bulbs; replace them when they become old and brittle.
Warnings & Risks
- Handle strong acids like hydrochloric acid and sulphuric acid with care, as they can cause burns if not handled properly.
- Incorrect preparation or use of reagents can lead to misidentification and failure in survival situations.
- Always wear appropriate personal protective equipment (PPE) when handling chemicals.
Modern Application
While the specific chemical reagents mentioned may differ from modern standards, the principles of using accurate measurements and proper storage remain crucial. This knowledge helps ensure correct identification of plant components during survival scenarios, whether for medicinal or nutritional purposes.
Frequently Asked Questions
Q: What is the purpose of the alcohol, glycerine, and water mixture in histological testing?
The alcohol, glycerine, and water mixture serves as a temporary mounting medium and can be used to qualitatively test for fixed oils. It helps preserve plant specimens for further analysis.
Q: Why is it important to use a 50 c.c. cylinder for measuring reagents?
Using a standard 50 c.c. cylinder ensures accurate measurements of micro-chemical reagents, which is crucial for the reliability and accuracy of histological tests.
Q: What are some safety precautions when handling strong acids like hydrochloric acid and sulphuric acid?
Always wear appropriate personal protective equipment (PPE) such as gloves, goggles, and a lab coat. Handle these chemicals in well-ventilated areas to avoid inhaling fumes.