JAK2V617F status of LM captured or cultured ECs from spleen or splenic veins. Shown are patient number 5 (lanes 3-6), patient number 6 (lanes 7-11 and 13), and patient number 9 (lane 12). Lane 1, JAK2V617F⁺ control; lane 2, JAK2 wild-type positive control; and lane 14, negative control. MW indicates molecular weight. Expected sizes for amplified fragments after digestion with BsaIX are 141, 30, and 12 bp for the wild-type allele, whereas the V617F allele remains undigested (183 bp). Both the 30- and 12-bp fragments derived from digestion of the wild-type alleles ran outside the gel. Heterozygous samples show both 183-bp (mutated) and 141-bp (wild-type) fragments.