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United States Government Work, uncopyrighted, public-domain,
DRAFT COPY ONLY. This document does not necessarily represent the views
or policies of any United States Government agency.
This document is provided "as is", without warranty of any kind,
express or implied, including but not limited to the warranties
of merchantability, fitness for a particular purpose and
non-infringement. In no event shall the authors be liable
for any claim, damages or other liability, whether in an
action of contract, tort or otherwise, arising from, out of,
or in connection with the document or the use or other dealings
made with the document.
See also: Main objectives: 1.
PRINCIPLE OF THE TEST.
All tissues are embedded in paraffin, for optimal histologic sections.
SPECIMEN REQUIRED.
All human tissue excised at surgery, outpatient clinics,
and postmortems, fresh or in fixative,
along with a filled-out Tissue Examination Form
(U. S. Standard Form 515, USSF515).
REAGENTS, INSTRUMENTATION.
Paraffin.
STEP-BY-STEP DESCRIPTION.
1. The cassettes are removed from the paraffin section of the
Tissue-Tek VIP® 5 Vacuum Infiltration Processor, in the Histology
Laboratory, 4D-124. See instructions on the front panel of machine,
and also INSTRUCTIONS FOR STARTING
TISSUE-TEK VIP®5 VACUUM INFILTRATION PROCESSOR,
in this procedure manual. At this time, the Tissue-Tek VIP® 5 Vacuum
Infiltration Processor is cleaned (or) purged. All tissues are embedded
in paraffin, except in case of bad weather or illness, the tissue
is set aside to dry.
2. The heating unit should be left on at all times so the liquid
paraffin can be dispensed into molds; however, the cooling unit is
turned off after the embedding is completed. To begin embedding, turn
on the cooling unit and forceps warmer. Empty all the cassettes
from the basket and place in paraffin reservoir section of embedding
center. This reservoir chamber is changed weekly with fresh clean
paraffin and noted on Quality Control sheets for embedding center.
The temperature is recorded daily on the entire unit.
3. Remove 6 to 8 cassettes; pinks, beiges, lavenders and yellows
are embedded first; (pink-biopsies, beige-Fort Howard, lavender-cytology,
yellow-bone marrows, white routines, green liver, grey Perry Point).
Remove the lids from the cassettes, being careful that the
tissue remains in the bottom of the cassettes. In general,
the resident will place face down in the plastic cassettes the surface
he or she wishes to be sectioned. Check the surgical gross worksheet (see
copy) to verify the amount of tissue present, and, if correct, check
the worksheet. Note any abnormalities, discrepancies and any embedding
instructions. For example, any tissue that resembles a tube should
be embedded on end, so that a cross-section will be obtained.
4. Fill the metal mold with paraffin half way to the top,
and place tissue at the bottom of mold. Place on cold plate. Press firmly,
and then place plastic cassette on top of mold and fill to the top
with paraffin. Be sure to select a mold of suitable size for the tissue
to allow for a margin of paraffin on all sides of the tissue, as this
facilitates in the ribboning during sectioning on the microtome.
5. While placing the tissue in the bottom of the metal mold, move
the mold onto the cold plate. Gently press down all edges of the specimen.
Too much pressure will produce crush artefact; too little may permit
an edge to lift up. This will result in an area of the tissue not
being sectioned, and not being seen by the pathologist while examining
under the microscope.
6. After filling metal mold with paraffin and placing a
plastic cassette on top of mold, place the entire unit on the
cooling plate and allow it to solidify. When completely cool,
the cassettes and specimen should
pop out of the mold easily. If not, tap the mold on a hard surface
to loosen the mold from the block.
7. When embedding is complete, put the metal molds into the upper
right hand chamber for warming. Every two weeks, metal molds are
placed in the chamber and purged along with the machine
for cleaning. After cleaning, metal molds are sprayed with mold release
spray. This is also checked off daily on Quality Control maintenance
log sheet.
8. The resident should be notified immediately if any tissue
is missing from cassettes according to daily worksheet, and also
if there is any mislabeling of cassettes. Embedding machine manual
is located in file drawer.
REFERENCES.
1. Prophet EB, Mills B, Arrington JB, Sobin LH.
Laboratory Methods in Histotechnology, pp. 39-44.
1992: Armed Forces Institute of Pathology,
Washington, DC. 20306-6000.
ISBN: 1-881041-00-X 1992.
2. Sakura Tissue-Tek® VIP® 5 Vacuum Infiltration Processor.
Operating Manual.
© 2001. Sakura Finitek, U.S.A., Inc.
Technical Support: 1-800-543-8496.
Sakura Finitek, U.S.A., Inc. © 2001.
1750 W. 214th Street
Torrance, CA 90501