NRAS_ EXON 2, 3 AND 4

Tumor Tissue
FFPE blocks or unstained slides , smears or cytospins.
Tissue should be prepared in sections 4-6 microns thick. H&E staining for FFPR and Pap stain for smear should be conducted for tumor content evaluation.
4 sections for large tissue section and 20 sections for small biopsies.
Tissue sections should be mounted on the positive side of an organosilane-coated slide.

The RAS proto-oncogenes encode a family of GDP/GTP-regulated switches that convey extracellular signals to regulate the growth and survival properties of cells. Mutation which change amino acid residues 12, 13 or 61 activate the potential of N-ras are implicated in a variety of human tumors. The specific genomic alterations have a clear prognostic role and are closely linked to response to specific anticancer agents.

NRAS mutation occur in ~1-6% of colorectal cancers. Wild type NRAS, together with wild type BRAF and KRAS are associated with response to EGFR antibody therapy. Somatic mutations in NRAS have been found in ~13-25% of all malignant melanomas and ~1% of all NSCLC. The NRAS mutation analysis real-time assay is based on allele specific PCR. Selection of tissue for the PCR assay should be performed by a pathologist.

Ambient (Room Temp) indefinitely
Refrigerated acceptable
Paraffin block - ambient room temp

Exposure of the specimen to acids, strong bases or extreme heat.
Frozen -20 °C unacceptable
Frozen -70 °C unacceptable