System for in situ processing of a tissue specimen
The present invention is directed to a system for use in the preparation in situ of tissue specimens for histological examination. The system includes a cassette, a specimen mounting card and a base mold. The invention also is directed to a method of processing a tissue sample for histological examination which does not require re-orienting the selected cutting plane in the specimen transfer step. Instead, the tissue sample remains oriented in a desired position throughout processing.
1. A system for use in processing a tissue specimen for histological examination comprising: a tissue specimen positioning member of a material that removably maintains the tissue specimen in a predetermined position thereon for providing the specimen with a known, consistent orientation throughout processing; a carrier member for receiving the positioning member with tissue specimen thereon and for subsequently mounting in a microtome the tissue specimen as processed to be associated with a fixing medium; and a base member having a lower recessed chamber sized to receive the tissue specimen positioning member with tissue specimen thereon and to maintain the positioning member therein upon application of a separation force between the positioning member and the tissue specimen for removing the tissue specimen from the base member.
2. The system in accordance with claim 1 , wherein the positioning member includes a first material for holding the tissue specimen in a generally fixed orientation when the tissue specimen is deposited on the positioning member and a second material for allowing separation of the tissue specimen from the positioning member upon application of a separation force.
3. The system in accordance with claim 2 , wherein the base member has a front wall and a back wall each having lines of weakness for facilitating breaking away of the walls from the base member upon application of a separation force to the walls to allow access into the interior of the base member for removal of the tissue sample from the positioning member contained therein.
4. The system in accordance with claim 3 , wherein the base member has an opening in the lower chamber sized for connection of a process line with the base member for introduction into and removal from the base member of fluids and air through the process line.
5. The system in accordance with claim 1 , wherein the lower recessed chamber comprises a removable bottom wall, a plurality of side walls having bottom edges, and a snap-fit connection between the bottom wall and at least one of the side walls.
6. The system in accordance with claim 5 , wherein the removable bottom wall defines a cartridge sized for receiving the positioning member such that a peripheral edge portion of a received positioning member is securable between a connected bottom wall and the bottom edge of at least one lower recessed chamber side wall.
7. The system in accordance with claim 6 , wherein the snap-fit connection comprises a protrusion on at least one lower recessed chamber side wall and a corresponding recess in the cartridge such that the protrusion is engageable within the recess to secure the removable bottom wall to the lower recessed chamber.
8. The system in accordance with claim 6 , wherein the snap-fit arrangement comprises a recess in at least one lower recessed chamber side wall and a corresponding protrusion on the chamber such that the protrusion is engageable within the recess to secure the removable bottom wall to the lower recessed chamber.