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

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• 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

References:

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.