Formalin-Formed Paraffin (FFPE) tissue samples have been a key element of research and therapeutic purposes for decades. FFPE is a form of storage and preparation of biopsy specimens that aids in research, experimental research, and drug diagnosis/development.
The tissue samples are first preserved by fixation in formaldehyde, also called formalin, to preserve proteins and vital structures in the tissue. Then embedded in a block of paraffin wax. This makes it easier to cut slices of the required size, which are placed on the microscopic examination glass. The process starts with taking a tissue sample.
Tissue is collected in various formats, for example from donors of sick and normal individuals. Another method is to match a pair of samples from the same person. In some cases, four samples were taken: healthy and diseased tissue for FFPE purposes and for clotting. However, there are so many tissue collecting centers such as https://www.geneticistinc.com/blog/storing-ffpe-blocks who collect the samples and test them.
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FFPE tissue is often used in a technique called immunohistochemistry (IHC), which involves placing tissue sites on a slide and then bathing them in a solution containing antibodies that bind to specific proteins or structures. The spots can then be used to visualize antibodies indicating which proteins or structures are present in the sample, along with their location.
The therapeutic areas where formalin and paraffin fixation is most often used are Oncology: FFPE tissue is key for oncology or cancer research because the preserved tumor tissue has a very distinctive morphology. Researchers often use the FFPE network to search for specific proteins. The presence of this protein can be used both in diagnosis and in assessing whether therapeutic antibodies might be useful in treatment.