• All IHC stains will include a positive control tissue

• Using polyclonal antibodies, a variety of human tissue types are recognized:
  
  • αα– myocardial and skeletal muscle cells
  • αβ– glial cells, melanocytes, chondrocytes, and adnexal glands
  • ββ– Schwann cells and Langerhans cells
• Pattern of S100 reactivity:

• S-100 protein is the most sensitive marker for melanoma; it stains amelanotic melanomas more strongly than pigmented tumors and usually detects desmoplastic and spindled melanomas (which are usually HMB45 negative)
• For melanomas, order both S-100 and HMB45 (if lesion is heavily pigmented, consider specifying the alkaline phosphatase (red) staining method.

Submit a formalin-fixed, paraffin embedded tissue block

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

• S-100 is a calcium binding protein that is composed of two subunits (alpha or beta) found in 3 different dimer forms.

 Staining pattern

• Cytoplasmic and nuclear based staining (should see both)