Hematopathology Laboratory
Specimen Handling
Liquid Specimens (peripheral blood, bone marrow aspirate, body fluids)
In general, liquid specimens should be anticoagulated (with the exception of CSF) and transported at room temperature as quickly as possible to the Hematopathology Laboratory. Heparin is the appropriate anticoagulant for most studies, although EDTA is preferred for molecular biology studies. Our testing does not require preservative-free heparin. Specimen requirements and handling may vary depending on a number of clinical factors; therefore the laboratory should be consulted prior to obtaining the specimen in order to optimize the information to be gained.
Tissue Specimens
The following may be used as general guidelines for handling lymph nodes, as well as other tissues that are to be sent to the Hematopathology Laboratory. It is important to call the laboratory at (206) 548-6231 for more specific instructions.
- Lymph nodes or other tissues should be transported from the operating room to your laboratory in sterile saline or tissue culture media (we use RPMI 1640 with 10% fetal calf serum). Wrapping the specimen in dry gauze tends to produce artifact due to drying. In addition, cells recovered from the tissue culture medium can be used for cell surface marker analysis by flow cytometry. A supply of tissue culture media may be obtained from the Hematopathology Laboratory.
- Transportation of the specimen to the Hematopathology laboratory: A representative section of lymph node should be placed in tissue culture media (RPMI 1640 with 10% fetal calf serum) and transported to the Hematopathology Laboratory (NW 225) as soon as possible. A specimen for cell surface marker studies should never be placed in fixative.
- If the specimen will take up to 12-14 hours to reach the laboratory, it should be transported in RPMI on wet ice.
- If the specimen will take longer than 24 hours to reach our laboratory, please consult with the laboratory for the best way to prepare the specimen for transport. We have found that embedding the specimen in O.C.T. or some similar compound used for frozen sections and then freezing it at -70°C is often a satisfactory way of protecting the specimen.
- Once the tissue is received in our laboratory, it will be frozen so that immunoperoxidase studies may be run the next day if necessary. If enough cells are recovered from the transport medium, cell surface marker studies will be performed by flow cytometry. This is often sufficient to make a diagnosis within hours of receiving the specimen. Depending on the results from flow cytometry, the frozen tissue may not be processed at all or only in a limited way. If there is some question on your part as to whether or not the specimen should be run (e.g. you suspect a reactive process and want to see the permanent sections before deciding whether lymphocyte surface markers would be helpful), ask our laboratory to "hold" the specimen. This means we will prepare the specimen, hold it at no charge, and only run the studies if you tell us to go ahead. If you do not tell us to hold the specimen, we will assume it is to be run as soon as possible.
- If only fixed tissue is available, it is still possible to perform some DNA-based testing on DNA isolated from paraffin blocks. If immunohistochemical studies are needed, we can forward the tissue blocks to Dr. Allen Gown's laboratory for immunocytochemistry.
- We appreciate any clinical information you are able to give us about the patient whose biopsy we will be studying. We use a standard battery of T and B cell antibodies, but any information you can provide is useful in helping us decide if additional antibodies are necessary. Providing clinical information often saves time in making a diagnosis. We also require an H & E stained permanent section of the biopsy we are processing. It is important to make sure the frozen tissue we have is representative and to correlate the morphology with the cell surface antigen findings. Please forward a recut of the H & E stained permanent section as soon as it is available.
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Last updated: 6/22/00
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