The process of preparing histological slides for examination is complex. Specimens must be fixed, processed, embedded into molds, sectioned into smaller portions, and stained before they can be examined under a microscope. Specialized specimens may also need to be stained in a special manner to ensure they appear brightly under the microscope.Continue Reading
Specimens must be fixed onto a slide in order to preserve them and prevent decomposition. Fixing the specimen involves washing the specimen with a series of solutions that dehydrate the tissues, clear the tissues, and infiltrate the tissues with medical paraffin.
Once the specimen's tissues have been infiltrated with liquid paraffin, they must be embedded into molds. Paraffin can turn into a solid once embedded into the mold and support the specimen.
After the embedding process is finished, the specimen is embedded into a paraffin block. This block must be sectioned in order to section the specimen and examine the various sections. The block is sectioned into smaller pieces using a rotary microtome. The sections are then placed in a freezer to chill.
Specimens can be stained to exhibit the different tissue components inside of the specimens. A variety of stains can be applied to the specimen to highlight different structures in the tissue specimens. Once stained, the specimens can be viewed under the microscope and examined.