• All IHC stains will include a positive control tissue

P53 over-expression is present in many different malignancies, such as colon, stomach, bladder, breast, lung, testes, melanomas, sarcomas, etc.

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

• P53 is a transcription factor that regulates cell growth and inhibits cells from entering S-phase
• P53 is a DNA-binding phosphoprotein coded for by a tumor suppressor gene located on the short arm of chromosome 17
• Mutations of p53 or functional inactivation with intact p53 genes are common in many cancers, leading to loss of normal growth regulation
• Although p53 is present in small amounts in normal cells (not usually detected by routine immunohistochemistry), mutations resulting in a prolonged half-lives lead to accumulations that are detected by immunohistochemistry
• Over-expression is associated with a poor prognosis in many cancers

Staining pattern

• Nuclear staining

References

1. Bartek J et al: Aberrant expression of the p53 oncoprotein is a common feature of a wide spectrum of human malignancies. Oncogene 1991; 6: 1699-703.