Assay performance

The RD-100i automates the OSNA assay and detects metastases in lymph nodes. The instrument automatically performs amplification and detection of special mRNA marker molecules (e.g. Cytokeratin 19 for » breast cancer metastases) Detection is carried out by a real time measurement of the turbidity of the reaction sample. The increasing turbidity is caused by a by-product of the amplification procedure. This is stoichiometrically generated during the reaction.

The results are displayed as 3 different categories, ++, + and - with a direct relation to copy number of mRNA marker molecules in the sample. The corresponding amount of marker molecules is indicated. The calculation of the concentration is based on the measurement of the risetime of 3 calibrator solutions. The risetime is defined as the point in time when the turbidity, caused by the advancing reaction, has reached a predefined threshold.

The time of amplification until results are displayed is 16 minutes.