We commonly receive questions regarding which fixative or chemical solution should be used when collecting tissue for testing. For the vast majority of cases, solid tissue collected during a surgical procedure or in-office biopsy should be placed in formalin (neutral buffered formalin). Please make sure the container is labeled with appropriate patient identifiers. A general rule is to have around a 20:1 formalin to tissue ratio to ensure adequate fixation. This can be difficult with larger specimens so in this situation, please add as much formalin as can be safely contained within the specimen container.
There are are few notable exceptions:
Bone Marrow: please review complete collection procedure here.
Lymph node or Soft tissue samples suspicious for lymphoma: Send sample to the lab on saline moistened gauze or telfa pad. Ensure sample reaches the pathologist quickly (<30 min) and confirm that sample has been received.
Kidney biopsy (Non-neoplastic): Three (3) kidney core biopsies are needed, all three samples must include renal cortex tissue. Two (2) cores can be placed in the same formalin container, and one (1) core should be placed in Michel media for immunofluorescence studies.
Samples for cultures: Cultures should be obtained during the procedure for optimal results. Collect tissue or wound cultures using culture swabs. The remainder of the tissue sample can be placed in formalin for additional analysis. Once the specimen touches formalin, tissue cultures cannot be obtained. If it is not possible to collect cultures during the procedure, place the tissue in an empty steril contain and send quickly to the lab.
Fine Needle Aspirations: Please review collection procedure here.
Skin biopsies for blistering or autoimmune disease: examples include bx for bullous pemphigoid, pemphigus vulgaris, lupus .etc. Two peri-lesional punch biopsies should be obtained (one in formalin and one in Michel media for immunofluorescence studies). Additional biopsy guidance can be reviewed here.
Skin biopsies for alopecia: Please review this paper for more information regarding hair loss.
If unsure of specimen collection requirements, please call our lab at 423 431 1310 and we will be happy to assist.
Specimen handling and collection
Watauga Pathology Associates
1725 W. Market Street
Johnson City, TN 37604