Histology is a field which studies the microscopic anatomy of animals and plants.  Thin slices of tissues and cells are examined by using an electron microscope or a simpler light microscope.  Many specializations of histology exist, but as a whole the science is a vital component of the health care industry as well as all fields of biology.  It is a centuries-old field, long considered an academic field all its own.  In 1906 a pair of histologists even won a Nobel Prize for their work on neural structure inside the brain, one for his theory concerning the structure and the other for developing a new staining technique that made the imaging possible.  

A number of different fields in biology and medicine utilize histology.  Anatomical pathology in particular relies heavily upon histology, using it to obtain accurate diagnosis of cancer or a multitude of other different diseases.  Trained pathologists most often perform examinations of tissue and cell samples to determine diagnosis and report their findings to a patient's physician.  Histotechnicians, also referred to as histology technicians, are specially trained scientists responsible for acquiring and preparing the tissue samples for examination by the pathologist and assisting them in operating and maintaining their laboratory.  Histology technicians often oversee the proper storage of tissue samples as well, usually by freezing them.  

Once the sample has been acquired, histology technicians apply chemical fixatives to the tissue to prevent degradation and preserve the sample.  A number of different fixatives are available, and each should only be used on the proper form of tissue.  The chemicals are far different depending upon the type of microscope that will be used to study the samples.   Freezing a sample by following a specific process is also an option for fixing a histological sample, and is done without chemicals by a device known as a cryostat.  This method of fixation is often used during tumor removal and allows doctors to quickly determine if the tumor has been totally excised or not.

After fixation has been successfully completed, the histology technician can begin tissue processing.  This process removes the water from tissue samples by replacing it with a solidifying agent.  Tissue must undergo solidification so that samples can be sliced thin enough to be viewed under a microscope.  Again, the method of magnification determines the chemicals used in tissue processing.  Paraffin wax is the most common choice for light microscopy, while epoxy resins are used if a sample is to be examined with an electron microscope due to the extremely thin sections required for such intense magnification.

Sectioning is completed using special knives, and very thin slices of the tissue sample are made and mounted onto a slide.  Staining the sample is the final process before a sample can be viewed.  The act of staining a sample supplies contrast to the nearly translucent sample, and can provide more intense highlighting of certain features in the tissue.  Hematoxylin is the most common dye used in the process, and stains the tissue with a color known as nuclei blue.  Hundreds of dye options exist, and each can be tailored to stain only certain cellular components or particular cells.  While these are the basics of histology, they only begin to scratch the surface of this multifaceted field of study.