Direct Immunofluorescence on Skin Biopsies

Direct immunofluorescence (IF) is a method for detecting deposits of immunoglobulin and complement in tissue specimens. The test is most commonly employed for skin biopsies where it can help to distinguish between various immunologically mediated diseases. The specimen has to be placed in a special fixative (Zeus fixative); direct immunofluorescence cannot be performed on formalin-fixed tissue.


  1. Call the Calpath office at least one day in advance if you require us to provide you with Zeus fixative.
  2. Place the biopsy is Zeus fixative.
  3. If regular histologic examination is required as well, two biopsies should be obtained, one submitted in formalin and one in Zeus fixative.
  4. Complete the Calpath requisition form per the instructions. State that the specimen has been placed in Zeus fixative for IF.

After collecting the specimen, please do the following:

  • Place the specimen in the Calpath specimen bag.
  • Place the requisition form in the side slot of the Calpath specimen bag.
  • Call Calpath for a pick-up or place the Calpath specimen bag in the location where our courier usually picks up your daily specimens.