It can be difficult for patients to understand what happens to their biopsy when the surgeon sends it to the pathology lab. One reason is that not all pathology labs are in the same office as where the procedure was done, they are usually sent off to a separate lab. To understand our process, we’ll take you through the steps that will occur in our in house pathology lab here at CADI.
Accessioning
As soon as your specimen, biopsy, arrives in our pathology lab, it is assigned an accession number as a unique identifier, which includes the Date of Service, Location and your DOB.
Grossing
Our histotechnologist will examine your biopsy and measure its size, while documenting the information in your electronic chart. The histo-tech then sections the tissue in equally thin slices and places all sections into cassettes. Cassettes are small rectangular boxes with multiple small openings in their walls which lets the chemicals (fixatives) bathe the tissue.
Fixation
This is a crucial part of the process. In order to make microscope slides, the tissue in the cassettes must be adequately treated in formalin, a fixative that solidifies the tissue and prevents the proteins within the cells from degrading. Fixation allows us to save your tissue for the required amount of years in our lab. The time needed for adequate fixation can be completed during the grossing process
Processing
After the tissue is solidified by fixation, it is gradually and progressively dehydrated in alcohols overnight in our Tissue Processing machine. This process takes about 8 hours to properly dehydrate the tissue.
Embedding
Tissues are embedded, using our embedding center, by placing them in a mold filled with melted paraffin wax, which is then allowed to solidify over a cold plate, and then is stable at room temperature indefinitely.
Your tissue blocks are filed and saved in our path lab, so at a later date a duplicate set of slides (re-cuts) can be made if needed.
H&E Slides
Thin sections (5 microns) of the tissue is cut from the block, that was just embedded, using a microtome (a cutting instrument), and carefully placed on slides. After slides are all made they are stained with what is called an H&E stain (Hematoxylin and Eosin). Hematoxylin stains the nucleus of the cells and Eosin, (referred as a counter stain), which stains nearly everything that the hematoxylin does not.
