Paraffin and Plastic Techniques for Preparation of Bone Marrow Specimen
Karen Noe, B.S., HTL (ASCP)
Muhlenberg Regional Medical center
Plainfield, NJ 07060
Handling of Bone Marrow
Aspirated Marrow Units:
- On the floor, about 5ml of marrow aspirate is placed into lavender top B-D vacutainer containing 0.07 ml 15% EDTA and mix the contents quickly and thoroughly.
- After arriving in the laboratory, the contents of the B-D tube are then filtered through either templefiber or Histowrap recovering only units.
- The units are wrapped in templefiber or Histowrap and placed in a bottle containing working B-5 Fixative. The units are fixed for 1 hour.
- The wrapped units are placed in a plastic processing cassette (do not use metal) and stored in 70% ethyl alcohol until processing.
Needle Biopsy of the Marrow:
- On the floor the biopsy material is placed in a bottle working B-5 fixative.
- After arriving in the laboratory, the biopsy is fixed in a minimum of 30 minutes; 1 hour preferable.
- After fixation, rinse the biopsy in tap water.
- The specimen is placed in RDO decalcifying solution for 15-30 minutes.
- When the decalcification is completed, the specimen is wrapped in lens paper, placed in a plastic bag processing cassette (no metal) and washed in running tap water for 30 minutes.
- Process as usual
Bone Marrow Biopsies
By Becky Scholes, HTL, MT (ASCP)
- Allow aspirate to clot in Petri dish.
- Transfer clot to specimen container filled with 10% buffered formalin.
- Process as usual.
Bone Core Fixation:
- Immediately fix in acetic formalin for a minimum of one hour.
- Fix overnight if brought in later than 2 hours before end of the work day. Decalcify first thing in the morning.
|Distilled water||1 part|
Bone Core Decalcifications:
- Place fixed core and label in a plastic cassette (RDO discolors metal). Decalcify in dilute RDO for 1 hour. Do not leave overnight.
- Test for decalcification by gently checking for pliability.
- Rinse in running tap water for approximately 2 minutes.
- If biopsy came in afternoon, process with the rest of the specimens.
- If the biopsy is decalcified in the morning, hand process in 120cc plastic specimen cups,
- 15 minutes in each container, starting with 70% ethanol or speed process through processor,
- 15 minutes each station with heat and vacuum, starting with the first dehydrant station.
- Cut both aspirate and bone cores at 2 microns.
- Place 3 levels on one slide. Cut an extra slide of the last level and set aside on the back of the water bath in case a special stain is requested.
- Hematoxylin approximately 5 minutes. Bone core 1 minute (check under the microscope before counterstaining).
- Eosin for 10 dips, dehydrate, clear and coverslip.
Over decalcification will result in poor or indifferent histological detail and staining characteristics. Less than one hour is usually not sufficient.