Table I.

Relative sensitivities of molecular diagnostic tests for CML

Method	Target	Sensitivity	Advantages	Disadvantages
Conventional Cytogenetics	Chromosomal translocation = t(9;22)	10%-5%	The gold standard, and detection of other large chromosomal changes.	Require dividing cells and highly skilled technician. Very labor and time intensive. Miss cryptic translocations.
Fluorescence in situ hybridization (FISH)	BCR-ABL1 DNA	0.1%-5%	Can use wider range of specimens (PB, BM, FFPE). Can detect cryptic translocations.	Relatively insensitive compared with qRT-PCR. Requires skilled technicians. Highly specific to targeted region and will miss other chromosomal changes.
Quantitative reverse transcription polymerase chain reaction (qRT-PCR)	BCR-ABL1 mRNA	0.001%-0.01%	Very sensitive. Can use wider range of specimens (PB, BM, FFPE). Can detect cryptic translocations.	Not well standardized across laboratories. More suceptable to contamination or RNA degradation issues.

CML = chronic myelogenous leukemia, PB = peripheral blood, BM = bone marrow, FFPE = formalin fixed parraffin embedded tissue