The OSNA (One-Step Nucleic Acid Amplification) assay is a RT-PCR-based technique for detecting CK19 mRNA. It is a quantitative, fast, and standardised assay, and it has been validated for lymph node molecular analysis in breast and CRC [11,12,13].
A novel technique for pathological examination, OSNA, uses the reverse transcription loop-mediated isothermal amplification method to amplify CK19 mRNA.