Preparation of Tissues for Histological Study

Tissues are examined via a light beam that is reflected through the tissue.

Tissues must be sectioned to obtain thin, translucent sections before they can be examined.

Oral histology is the study of teeth and its supporting tissues in the oral cavity.

Scanning electron microscope is commonly used for studying tissues.

Decalcified section is used for tissues containing bone or teeth.

There are 4 common types of sections for studying tissues.

Enamel of the tooth contains 96% minerals, so it is completely destroyed if decalcified unless it is still not fully formed and can be seen.

Specimens of calcified tissue may be ground into thin sections such as bone and undecalcified tooth.

Frozen section is used to examine the pathological tissue specimens immediately, or if the reagent used for embedding would destroy the tissue characteristics that are to be studied.

The purpose of fixation is to coagulate the protein, thus reducing alteration by subsequent treatment, and to make the tissue more permeable.

The most commonly used fixative agents for light microscopical examination are 10% neutral buffered formalin and Bouin's fluid.

The specimen is gradually dehydrated by being passed through a series of increasing percentages of alcohol.

Paraffin and alcohol are not miscible, so the specimen is passed from alcohol through changes of xylene, which is miscible with both alcohol and paraffin.

The tissue is embedded in melted paraffin and allowed to harden into a paraffin block and then sliced into thin sections for light microscopical study.

The process of embedding is done in order to distinguish the overlapping cells in a tissue and the extracellular matrix from one another.

The paraffin blocks are sectioned with a microtome, which is a device supplied with a stainless steel blade and an arm that can provide us with equal increments of the tissue thickness.

Tissues are examined via a light beam that is transmitted through the tissue.

Decalcified section is used for tissues containing muscles and tendons.

Fixation is done to make the tissue less permeable.

The enamel of the tooth contains 96% minerals, so it can be easily decalcified.

Scanning electron microscope is commonly used for studying tissues.

The specimen is gradually dehydrated by being passed through a series of decreasing percentages of alcohol.

Enamel of the tooth contains 96% minerals, so it is completely destroyed if decalcified unless it is still not fully formed and can be seen.

Specimens of calcified tissue may be ground into thin sections such as bone and undecalcified tooth.

Frozen section is used to examine the pathological tissue specimens immediately, or if the reagent used for embedding would destroy the tissue characteristics that are to be studied.

The purpose of fixation is to coagulate the protein, thus reducing alteration by subsequent treatment, and to make the tissue more permeable.

The specimen is gradually dehydrated by being passed through a series of increasing percentages of alcohol.

Paraffin and alcohol are not miscible, so the specimen is passed from alcohol through changes of xylene, which is miscible with both alcohol and paraffin.

There are 4 common types of sections for studying tissues.

Scanning electron microscope is commonly used for studying tissues.

Tissues must be sectioned to obtain thin, translucent sections before they can be examined.

Oral histology is the study of teeth and its supporting tissues in the oral cavity.