Today, there are many commercial kits for detecting BCR-ABL fusion transcripts. The QXDx™ BCR-ABL %IS kit (Bio-Rad, Hercules, CA, USA) is the first ddPCR-based in vitro diagnostics (IVD) product with the US Food and Drug Administration clearance and European Conformity (CE) mark which launched in 2017. Dr. PCR™ BCR-ABL1 Major IS Detection Kit (Optolane, South Korea) is one of CE-IVD commercial kits based on digital RT-PCR. Both commercial kits are digital PCR-based, also evaluated their correlation, pros and cons in order for users to select a reagents kit that are appropriate for themselves.

Today, there are many commercial kits for detecting BCR-ABL fusion transcripts. The QXDx™ BCR-ABL %IS kit (Bio-Rad, Hercules, CA, USA) is the first ddPCR-based in vitro diagnostics (IVD) product with the US Food and Drug Administration clearance and European Conformity (CE) mark which launched in 2017. Dr. PCR™ BCR-ABL1 Major IS Detection Kit (Optolane, South Korea) is one of CE-IVD commercial kits based on digital RT-PCR. Both commercial kits are digital PCR-based, also evaluated their correlation, pros and cons in order for users to select a reagents kit that are appropriate for themselves.

Objectives 1.To evaluate and comparison of BCR-ABL p210 mRNA transcripts (%IS unit) results from two detection kit ; Dr. PCR™ BCR-ABL1 Major IS Detection Kit (Optolane) VS QXDx™ BCR-ABL %IS Kit (Bio-Rad) in chronic myeloid leukemia (CML) patients Secondary objective 2.To be used as a standard inspection method of the Hematology laboratory at Siriraj Hospital Inclusion criteria

1. Leftover RNA samples from CML patients were recruited from the Hematology Laboratory Division of Hematology Department of Medicine Faculty of Medicine, Siriraj Hospital Mahidol University, after TKI treatment and regular follow-ups or newly diagnosed.
2. All samples were successively tested by QXDx™ BCR-ABL %IS Kit (Bio-Rad) which used Droplet Digital PCR (ddPCR) technique.

Exclusion criteria

1.In adequate or poor-quality specimen

Inclusion Criteria:

• Leftover RNA samples from CML patients were recruited from the Hematology Laboratory Division of Hematology Department of Medicine Faculty of Medicine, Siriraj Hospital Mahidol University, after TKI treatment and regular follow-ups or newly diagnosed.
• All samples were successively tested by QXDx BCR-ABL %IS Kit (Bio-Rad) which used Droplet Digital PCR (ddPCR) technique.

Exclusion Criteria:

• In adequate or poor-quality specimen

The patients 18 years and older who were newly diagnosis and known to have CML

IPD are available from the corresponding author on reasonable request.