The study of anatomy of cells and tissues of plants and animals is called Histology. Histology revolves around studying things on a microscopic level, so it involves the use of microscopes. Specimens are usually put onto slides, where they can be studied from the microscope easily. Histology helps progress biology in almost every way, as it helps better understand living organisms on a microscopic level.

Histology's origins date back to the 17^th century, when Italian Marcello Malphighi invented a microscope capable of studying small biological entities. He would analyze many organs from a variety of animals including bats and frogs. This helped give deeper understanding to the animals and unlocked new and interesting facts about them.

Malphigi would go on to discover capillaries, small hair connections between arteries and veins. He would also discover how oxygen enters the blood stream and helps bodies function. By the 19^th century, histology became a well-developed school of science. In 1906 the first histologists would win the Nobel Prize, Camillo Golgi and Santiago Ramon y Cajal.

There are a few stages to preparing samples for examination which varies based on what scientists are studying. For example, if scientists want to preserve tissue from degradation, they use chemicals to do so. Another way is through frozen samples, which can be frozen rapidly with a device called a cryostat. This is especially useful during surgeries removing tumors, as it allows rapid examination of tissue to ensure the tumor has been completely removed.

The next stage is processing. Tissue Processing's main goal is to remove the water in tissues and replace them with solids, allowing it to be cut easily. Depending on how scientists examine specimens determines what substance to use to enable to processing method. An example of this would be if they were using a light microscope, paraffin wax is used frequently.

Once the water has been removed and the specimen is to the appropriate status, the final step of processing is infiltration. This is done with the use of a hydrophobic clearing agent, such as xylene. This removes the alcohol and then the molten paraffin wax can be inserted, which replaces the xylene.

After this stage comes embedding. The material is placed into molds with a liquid that solidifies the material into place through rapid cooling and heating (also called curing). Because DNA and RNA can both be examined decades after embedding, it is exceptionally important to preserve this data for future studies.

The final two stages are sectioning and staging. Sectioning, in the example of light microscopy, is taking a steel knife and cutting 4-micrometer-thick sections of tissue which are then mounted on a microscope slide made of glass. For other examinations, such as transmission electron microscopy, a diamond knife is used to make 50-nanometer-thick sections in the tissue.

Staining allows for biological tissue to be seen better in the microscope. Because biological tissue contrasts with light and electron microscopes, staining is essential to observing anything under the microscope. Hematoxylin and eosin (H&E Stains) are the most common chemicals used to stain.

Though these processes can be long and tedious, it is ever important. Not just for histology, for most life sciences such as the various branches of biology. It allows for a deeper understanding at a microscopic level to our organs and other biological material on the planet.

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