HER2 status in breast carcinomas can be determined by testing with any of the following methods:
- Gene amplification can be identified by Southern blot, polymerase chain reaction (PCR), or fluorescence in situ hybridization (FISH)
- mRNA levels can be assessed using Northern blot
- Protein overexpression can be measured via enzyme-linked immunosorbent assay (ELISA), Western blot, or immunohistochemistry (IHC)