The Xpert BCR-ABL1 p190 Linearity Panel C208 is intended for use as reference material to monitor the reportable range of in vitro quantitative detection of the p190 BCR-ABL1 translocation mRNA transcript and the ABL1 endogenous control mRNA transcript when analyzed using the Xpert BCR-ABL Ultra p190 assay on Cepheid GeneXpert Instrument Systems. The Xpert BCR-ABL1 p190 Linearity Panel C208 consists of 6 components. Each component contains an increasing concentration of BCR-ABL1 (e1a2) RNA transcript mixed with a fixed concentration of ABL1 RNA transcript to produce 6 levels, 0.008%, 0.02%, 0.1%, 1%, 10%, and 20%. Each ratio of e1a2 RNA to ABL1 RNA has been confirmed by digital PCR. Assessing the linearity of an assay is a crucial part of good laboratory practice, as it confirms that the test system accurately measures patient samples throughout the manufacturer’s designated reportable range.