How is a cell and tissue (histology) test performed?
Use of the microscope is very important in the study of tissue structure and cells with unusual appearances. It is, for example, possible to diagnose cancer, as cancer cells very often have an unusual shape and form irregular patterns. When the pathologist receives a biopsy (tissue sample) it is separated into small pieces that are dipped into formalin or a similar fixing chemical. The fixed tissue is then placed in paraffin before being cut into extremely thin slices, which can be placed under a microscope. The paraffin is then removed, and the tissue is stained to make the microscopic details easier to see. Then it is ready for microscopy. If certain types of cells are expected to be present, the sample can be stained in colours that are particularly helpful in detecting them. Unfortunately, it can sometimes take up to a week before the result of a tissue test is ready. Sometimes it takes even longer if the sample needs further staining. In an emergency, the result can be ready withi
