Staining is a technique used in microbiology to enhance and contrast a biological specimen at the microscopic level. Stains and dyes are used to highlight the specimen at the microscopic level to study it at higher magnification for histopathological studies and diagnostic purposes. Staining is not just limited to biological specimens, it can also be used to study the structure of crystalline polymers. Before a sample can be viewed under a microscope, it needs to be mounted onto a microscope slide. The preparation of the biological specimen to be analyzed under a microscope depends on the type of staining. There are different types of staining techniques, including simple staining and differential staining. Simple staining is a staining procedure that uses only one stain, and all types of bacteria appear as the color of that stain when viewed under the microscope. Some stains commonly used for simple staining include crystal violet, safranin, and methylene blue. Simple stains can be used to determine a bacterial species’ morphology and arrangement, but they do not give any additional information/04%3A_Staining_Techniques/4.01%3A_Introduction_to_Staining). Differential staining involves the use of more than one stain, and cells will have a different appearance based on their chemical or structural properties. Some examples of differential stains are the Gram stain, acid-fast stain, and endospore stain. Differential staining methods are used more often than simple stains as a means of gathering information about bacteria.