Embedding Techniques PDF

EMBEDDING / BLOCKING - most commonly used - encasing an infiltrated tissue sample in a medium while in a cast Paper boat should be 1-2 inch or each side — ideally 1 (mold) that will aid...

EMBEDDING / BLOCKING - most commonly used - encasing an infiltrated tissue sample in a medium while in a cast Paper boat should be 1-2 inch or each side — ideally 1 (mold) that will aid in the microtomy process inch is enough - ensures that tissues are cut uniformly and will minimize the tendency of destroying the entire tissue sample Peel-Away - made in plastic — peelable mold - whatever the infiltrating medium used, the same material is used during - can melt when overheated the embedding process - in its somewhat warm, but still molten state, an embedding medium is Plastic Ice Trays - can accommodate numerous specimens poured in a mold and is allowed to cool, but not solidified - difficult to remove — when embedding ice trays - the tissue sample is placed in the cooled embedding medium, placing it in a certain way, then the remaining space in the cast is filled with the REUSABLE EMBEDDING CASTS embedding medium - more expensive but can be reuse Paraffin most commonly used wax for both infiltration and embedding Leuckhart’s - most commonly used - ideal temp: 56-58℃ Embedding Mold - put initial wax before adding the tissue - cooling down temp: room temperature - adjustable 2-piece brazz; must not pour hastily usually require a casts or mold — cheapest would be paper boat to keep size - accommodate the size of tissue ORIENTING Compound - similar to ice trays; accommodate numerous; - a process where tissues are placed in a certain way inside the cast to Embedding Unit most expensive demonstrate the required structure on the tissue section - tissues are placed in cassettes in a way that they must be placed in Plastic Embedding - NOT peelable the tissue block Rings and Base - heat resistant - ensures proper interpretation by the histopathologist (longitudinal, Molds - ex. Tissue Tek System cross-section, oblique section) pathologic parts should be facing downwards and flat IMPORTANCE OF AND CONSIDERATIONS ON EMBEDDING Whatever the infiltrating medium used, the same material is used for blocking EMBEDDING MOLDS ○ to avoid wrinkling - casts with a preset shape Trimming is necessary to fit the blocks inside the tissue block holder - allows the medium to cool and solidify according to the shape of the of the microtome recess of the mold ○ regular knife can be used - depending on the type of mold, blocks may require trimming so that it A dense embedding medium is necessary for blocking tissues to be cut will fit inside the tissue block holder of the microtome with a heavy microtome knife There must be at least a 2 mm gap /