The current first-line therapy of chronic myeloid leukemia (CML) is based on tyrosine kinase inhibitors. Diagnostic kits that are capable of identifying at least a 4.5 log reduction in the international scale % BCR-ABL/ABL (IS % BCR-ABL/ABL) are needed for use in the clinical evaluation of deeper molecular response to treatment and to determine the timing of dose selection or treatment interruption during the course of treatment. In this study, we evaluated the performance of a new diagnostic kit, ODK-1201, designed to be capable of performing reverse transcription and quantitative PCR in a single tube for the quantitation of major BCR-ABL mRNA. The kit demonstrated excellent assay performance (limit of detection 0.0007 %) and a broader detection range of BCR-ABL mRNA in peripheral blood compared to a commercially available kit for CML (Amp-CML). ODK-1201 was also shown to be as sensitive as Ipsogen and Molecular MD kits in the same assay. Results obtained in this study indicate evidences that ODK-1201 was capable of identifying at least a 4.5 log reduction in the IS % BCR-ABL/ABL.