Tissue specimens should be placed in a sterile cup with sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline within one (1) hour of the procedure.

Paraffin block or 5 micron cuts mounted on positively charged slides

• Allow specimen to fix in 10% neutral buffered formalin for 6 - 72 hrs
• Prepare a formalin-fixed, paraffin-embedded (FFPE) tissue block
• Submit the FFPE tumor block (an H&E will be cut and stained, and assessed by an HPA pathologist) or 2 unstained slides and 1 H&E 

FFPE block

Slides

• Cytogenetics oncology requisition
• Document time in fixation – specimen should be fixed in 10% neutral buffered formalin for 6 - 72 hrs

Ambient

• Improper label (unlabeled or mislabeled)
• Wrong container (anticoagulant or solution)
• Improper storage
• Leaking container
• Slides broken beyond repair

Fluorescence in situ hybridization (FISH)

Positive (Amplified) result – 25 cells scored with an MDM2:CEP12 ratio ≥2.0

Negative (Non-amplified) result - 25 cells scored with a MDM2:CEP12 ratio <2.0