Saliva’s abundant leukocytes allow it to be an adequate noninvasive alternative to blood for genetic material. (A) Flow cytometry (top) and cytospin histology (bottom) of saliva from a healthy control and patient with essential thrombocythemia. Red arrows indicate leukocytes, and blue arrows indicate buccal epithelium. (B) Distribution of the genomic DNA concentrations isolated from blood (n = 570), saliva (n = 1670), and nails (n = 72); blood and saliva were eluted in 100 μL, and nails were eluted in 50 μL. Input amount of blood, saliva, and nails was 400 μL, 400 μL, and 20 mg respectively. (C) Concurrent blood and saliva samples were obtained from 49 patients with MPN, and JAK2V617F allele burden was measured by dPCR (r2 = 0.8931; P < .0001). Line of best fit, black; line of actual VAF, red.
