COMMONLY USED DEHYDRATING AGENTS

Ethanol

• Nontoxic

• Fast acting

• Reliable

• Inexpensive and easily obtained

Ethanol

• Miscible in all proportions with water

• Little shrinkage if graded alcohols are used

Ethanol

Can be used on eyes and embryos, if graded alcohols are used

Ethanol

Still considered best dehydrating solution

Ethanol

Appears to cause less extraction of cellular components in general than other agents

Ethanol

• It is a clear, colorless, flammable fluid. It is considered to be the best dehydrating agent because it is fast-acting.

• It is not poisonous and not very expensive

Ethanol

• Expensive

• May be difficult to obtain

Ethanol

• Long periods i n absolute ethanol will cause excessive shrinkage and hardening

• May cause more shrinkage of specimen

Ethanol

• May react with an unreduced 0s04 remaining in specimen

• Only slightly miscible with most resins

Ethanol

May have prohibitive taxes that necessitate troublesome book-keeping

Ethanol

• Extracts methylene blue and other thiazine dyes from sections

• Extracts more lipids than acetone

Butanol

Less shrinkage and hardening than with ethyl

Butanol

Excellent for slow processing

Butanol

Miscible with paraffin

Butanol

• Odorous

• Slow-acting

Butanol

• Long periods of infiltration necessary

• Dehydrating power low

Butanol

which is utilized in plant and animal micro-techniques, is a slow dehydrating agent, producing less shrinkage and hardening than ethyl alcohol and is recommended for tissues which do not require rapid processing.

Methyl alcohol

is a toxic dehydrating agent, primarily employed for blood and tissue films and for smear preparations

Tertiary butanol

• Universal solvent—acts as dehydrating and clearing agent

• Mixes with water, ethanol, xylene, and paraffin in all

Tertiary butanol

May be used in staining series as a dehydrating agent

Tertiary butanol

• Odorous

• More expensive than butanol

Tertiary butanol

Primary infiltration must be done in half tertiary butanol and half paraffin, prior to paraffin impregnation

Tertiary butanol

Reagent tends to solidify at room temperature or below 25° C

Isopropanol

• Excellent substitute for ethanol

• Less shrinkage and hardening than ethanol

Isopropanol

• No government restrictions on its use

• Less expensive than tax-free alcohol

Isopropanol

Lillie considers it “the best all- around substitute for ethyl alcohol”

Isopropanol

Sufficiently water-free to use in place of absolute ethanol

Isopropanol

Cannot be used in the celloidin technic since nitrocellulose is insoluble in it

Isopropanol

Cannot be used for preparing staining solutions, since dyes are not soluble in it

Pentanol

Miscible with 90% alcohol, toluene and xylene

Pentanol

Dissolves paraffin wax

Pentanol

• Toxic

• Not miscible with water

Pentanol

Cannot be used in poorly ventilated rooms