Detection of the JAK2 G1849T mutation in peripheral lymphoid cells from IMF and PV patients. Peripheral granulocytes and lymphocytes from JAK2-mutated IMF and PV patients were isolated using standard density, immunomagnetic, and flow cytometric methods for further DNA extraction and sequence analysis. The JAK2 G1849T mutation was detected in some lymphoid cells from a majority of IMF patients and a minority of PV patients. The sequence traces of granulocytes and T, NK, and B cells from 2 IMF (patients IMF9 and IMF7) and 2 PV patients (patients PV2 and PV8) are shown; – indicates that the mutation was not detected. Red arrows indicate the presence of a mutant peak. Semiquantitative estimate of the percentage of mutated allele is presented on each sequence trace.