Procedure to obtain a biopsy for direct immunofluorescence
Skin or mucosal tissue specimens for direct immunofluorescence can be sent in transport medium (Michel's/Zeus) or frozen on dry ice. Transport medium is more practical in most circumstances.
Note that direct immunofluorescence cannot be performed on specimens fixed in formalin. Specimen kits are available with transport tubes containing medium and fixative (formalin) and can be easily ordered.
Supplies and equipment needed
- Specimen vial(s) containing transport medium (Michel's or Zeus medium) or dry ice, specimen vial containing formalin for fixed tissue studies if indicated, and serum vial (contact the Immunodermatology Laboratory for free specimen kits).
- Forceps to transfer specimen into vial
- Biopsy instruments to obtain biopsy
- Blood draw supplies (Red top tube, transfer pipette, etc.)
- Choice of the correct skin or mucosal biopsy site is critical. For those diseases in which perilesional specimens are required and appropriate sites are limited, a larger biopsy can be taken to include involved and perilesional tissue and then divided. Be certain to maintain orientation of the tissue as it is removed so that the perilesional and involved tissue parts are appropriately submitted; perilesional tissue for direct immunofluorescence and the involved lesional piece for fixed tissue histological examination. (Note - specimens submitted in formulin may be sent for Dermatopathology evaluation only.)
- 4-mm or 5-mm punch biopsy specimens are preferred. If a biopsy specimen is to be divided for fixed tissue study along with direct immunofluorescence, use at least a 5-mm punch. A deep shave or an excisional biopsy may be obtained. If dividing the specimen, cut with a very sharp blade such as a scalpel or razor, making a clean cut. Do not compress, pinch or crush the specimen. Divide specimens larger than 5 mm in diameter for adequate fixation.
- Immediately place the specimen for direct immunofluorescence into a vial of transport medium or on dry ice. Seal vial tightly. Label the vial with patient's name, date of birth, biopsy site, and date. If another specimen is submitted for direct immunofluorescence, identify the specimens accordingly and label each. If a specimen is submitted for fixed histology, place the specimen in formalin, seal tightly, and label the vial with patient's name, biopsy site, and date.
- Blood specimens should be drawn in a plain, red-top tube or an SST tube. Spin down by centrifugation and send 2.0 mL or more of serum in the vial provided. This vial has a sealing ring to prevent leakage. A minimum of 0.5 mL serum is required; however, if you have collected less and it is all that you can collect, please send it, and we will perform as much of the testing as possible. If a centrifuge is not available, stand the blood tube upright in the refrigerator for 2 - 3 hours and then use a transfer pipette to pull off the serum and place in the provided cryovial.
- Upon completion of the Specimen Request Form, review the transportation instructions.