Assay performance

The RD-100i automates the OSNA assay and quantitatively 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, macrometastases (++), micrometastases (+) and no metastases (-) with a direct relation to copy number of mRNA marker molecules in the sample. The corresponding amount of marker molecules is indicated and the system gives a quantitative overview. 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.