S100 recognizes proteins of 21-24kDa, identified as the A and B subunits of S100 protein. S100 belongs to the family of calcium binding proteins such as calmodulin and troponin C. S100A is composed of an alpha and beta chain whereas S100B is composed of two beta chains. Antibody to S100 stains Schwannomas, ependymomas, astrogliomas, and almost all benign and malignant melanomas and their metastases. S100 protein is also expressed in the antigen presenting cells such as the Langerhan’s cells in skin and interdigitating reticulum cells in the paracortex of lymph nodes. The diagnosis of Histocytosis X is confirmed by S100 staining. S100 PAb is excellent for immunohistochemical staining of formalin-fixed, paraffin-embedded tissues. S100 protein is highly soluble and may be eluted from frozen tissue during staining.
Human, Mouse, Rat
Cytoplasmic and nuclear
Melanoma or Schwannoma
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