Sensitivity of PCR detection of FLT3/ITD.

gDNA isolated from a patient relapsing with a 100% FLT3/ITD level (patient 1) was diluted by mixing with various amounts of DNA from the HL-60 cell line (FLT3/ITD⁻) to yield final concentrations of positive DNA at levels of 0.5%, 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, and 35%. Undiluted HL-60 DNA served as a negative control (N) and undiluted DNA from patient 1 as a positive control (P). PCR was performed as described in “Materials and methods.” ITD indicates FLT3/ITD allele; WT, wild-typeFLT3 allele.