Clearing Agents

Can be used with celloidin sections

Carcinogenic or may damage bone marrow (Aplastic anemia; If antibiotic: Chloramphenicol)

Not suitable for routine purposes because it is expensive

An excellent and true clearing agent

It removes aniline dyes and dissolves Celloidin; Tissues become brittle

It does not make tissues transparent and it is toxic to the liver (hepatotoxic) after prolonged inhalation

Clears both Paraffin and Celloidin sections

The most rapid clearing agent

Quality is not always uniform and good and is extremely slow

It causes considerable hardening and shrinkage of tissues; hence, is not suitable for nervous tissues and lymph nodes.

Substitute to xylene or benzene

Urgent biopsy clearing time of xylene

Clearing time of benzene

These are slow-acting clearing agents that can be used when double embedding techniques are required.

Toxic on prolonged exposure

Rapid acting, recommended for urgent biopsies and routine purposes

clearing time of cedarwood oil

Properties are very similar to chloroform but it is cheaper

It becomes milky on prolonged storage

It is recommended for tough (skin, fibroid and decalcified tissues) and large tissue specimens

clearing time of chloroform

It is the best of the traditional clearing agents for routine use

Gives the widest latitude

It is miscible with absolute alcohol and paraffin

Causes minimum shrinkage of tissues

Cheap and does not extract out aniline dyes

Block size for xylene

It is slower in action than xylene, but causes less brittleness

Highly flammable

Usual clearing time of xylene

Clearing time of toluene

Its quality is not guaranteed due to its tendency to be adulterated

Recommended for clearing embryos, insects and very delicate specimens since it clears 70% alcohol without excessive tissue shrinkage and hardening

If tissue or section is incompletely dehydrated, it becomes milky

Recommended for CNS tissues and cytological studies (esp. Smooth muscles and skin)

Dehydrates and clears at the same time since it is miscible in both water and paraffin

Best for nervous tissue, lymph nodes, granulation tissue, and fetal and other delicate, highly cellular specimens, all of which tend to become distorted and to break up on sectioning if cleared in xylene, toluene, or benzene

It is not carcinogenic but highly concentrated emit fumes that are toxic upon prolonged exposure

Very expensive and it requires 2 changes in clearing solution

It acts slower than benzene and is expensive