Glial fibrillary acidic protein by IHC

Alphabetical Test listing

Glial fibrillary acidic protein by IHC-12376 - Technical only, 12379 - Technical & interpretation

Glial fibrillary acidic protein by IHC
12376 - Technical only, 12379 - Technical & interpretation

All IHC stains will include a positive control tissue


This antibody is useful in identifying astrocytomas (you may see less staining in high grade tumors). The characteristic "cap-like" pattern may be helpful in identifying oligodendrogliomas. Ependymomas and PNETs can show variable GFAP staining.



Submit a formalin-fixed, paraffin-embedded tissue


Formalin-fixed, paraffin-embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

  • Unlabeled/mislabeled block
  • Insufficient tissue
  • Slides broken beyond repair
AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination


If requested, an interpretive report will be provided



  • Identifies the intermediate protein GFAP (52155KDMW) in brain and spinal cord in benign and malignant tissue
  • GFAP is present predominantly in astrocytes and some ependymal cells (not present in ganglion cells, meningothelial cells, neurons, or fibroblasts)
  • In normal brain, protoplasmic astrocytes contain little GFAP while fibrous astrocytes show abundant GFAP
  • Occasional GFAP reactivity is seen in: Schwann cells and schwannomas; folliculostellate cells of anterior pituitary, some choroid plexus tumors; some "non-neural" tissues and tumors
  • Macrophages can phagocytize GFAP and therefore react positively
  • Oligodendrogliomas can be negative for GFAP or can show a characteristic "cap-like" pattern which can be helpful

 Staining pattern

  • Cytoplasmic based staining


  1. Royds, JA et. al: An Immunohistochemical Study of Glial and Neuronal Markers in Primary Neoplasms of the Central Nervous System; Acta Neuropathol 70:320-326, 1986.
88342 - 1st stain
88341 - each additional stain