#Histology processing steps full#

This step is to be performed with caution if the goal is to perform immunostaining because the paraffin wax will inhibit the penetration of antibodies, and lead to a false result. Д®mbedding:В Embedding is the process of putting the sample into a paraffin wax or a plastic resin to enhance the process of extracting cellular structures. After ethanol is applied, and following the completion of tissue dehydration, xylene is used to remove the ethanol. It removed water from the sample and further hardens the tissue for eventual light microscopy. Дehydration: The addition of ethanol accomplishes the dehydration of a sample. Its downside is that it does not preserve kidney tissues well and also distorts mitochondrial structure.

Bouin is a fixative used for examining embryo and brain tissue because of its superior preservation of delicate nuclei and glycogen. Its benefit is that it is the fixative of choice for immunostaining however, it requires preparation at the time of the fixation. Paraffin-formalin is another effective fixative. The fixation step is vital to the rest of the histologic staining procedure because by retaining the chemical composition of the tissue, the sample is hardened and makes the sectioning phase easier. Although several specialized fixatives are available, Neutral Buffered Formalin is a common choice for this step. In modern histology laboratories, most of these steps are automated.ДЇixation: Fixation uses chemicals to preserve the structure of the tissue in its natural form and protects it from degradation by irreversibly cross-linking proteins. Tissue PreparationД«efore specific staining can occur, tissue samples must undergo preparation through the following stages: Fixation, processing, embedding, sectioning, and sometimes antigen retrieval. These stains are used for the identification of specific types of tissue and identification of abnormal tissue, so a subsequent biopsy can be more accurate in obtaining abnormal tissue. However, in rare instances, very specialize stains called vital stains can work on tissue remaining in the body. FunctionДЄlmost all tissue stains are performed on tissue that has been removed from the body.

#Histology processing steps full#

For this reason, multiple slides will often be created from a given specimen so that multiple stains can be performed to gather the full range of needed information. However, because of its specificity, the other structures will not be seen. The benefit of using a special stain is that it can highlight the specific protein very well. Because of the variety of the proteins that exist, some stains were created to highlight a particular protein, which this review will discuss in the following sections. These two stains are commonly used together to define intracellular organelles and proteins. For example, one of the most common stains, Hematoxylin, is a basic dye that stains proteins a blue color, while Eosin stains proteins a pink color. Each stain exists to highlight an important feature or component within a tissue type. Epithelium, connective tissue, muscle tissue, and nervous tissue have commonalities but look very distinct structurally after staining. StructureДЇour basic types of human tissue can be stained and viewed using various histological techniques. It is not always the case that the interpreting pathologist has thoroughly analyzed the tissue sample by including appropriate histologic staining, and this deficiency can retard accurate diagnosis. Issues of ConcernД«asic knowledge of tissue preparation, including staining, is important to know when interpreting pathology reports on either in-patient or out-patient biopsies. Advanced interpretation of the histology slide combined with a patientвЂ™s medical history can make an invaluable impact on the treatment course and prognosis. The histological stains chosen for a given specimen depends on the investigational question at hand. Once the tissue sample has undergone fixation, processing, embedding, sectioning, and staining, it can undergo analysis through microscopy and the findings interpreted by a pathologist. Because of this, it is utilized in medical diagnosis, scientific study, autopsy, and forensic investigation. Often called microscopic anatomy and histochemistry, histology allows for the visualization of tissue structure and characteristic changes the tissue may have undergone. Medical Histology is the microscopic study of tissues and organs through sectioning, staining, and examining those sections under a microscope.