A permanent section is a technique used in preparing tissue to be examined under the microscope. To make a permanent section, the following procedure, which takes 1-2 days, is performed:
A biopsy sample is immersed in formaldehyde, followed by soaking in other chemicals. Next. the chemically-treated tissue is covered on all sides in a block of paraffin wax. Then, thin slices (called thin sections) of the block are made. and each section is placed on a separate glass slide. The slides are stained with dyes.
A pathologist (a doctor who specializes in laboratory diagnosis of disease) examines the stained slides under the microscope and interprets them to determine whether the tissue shows evidence of disease (such as the presence of cancer cells).