“…Lastly, a fourth group found that differences in hematocrit (20% to 45%), spotted blood volume (25,35,50,75, and 100 μL), and punch location did not affect immunosuppressant quantitation [39]. [46,47] Online solid phase extraction (analytical run time of 1 min) [48] No LC separation (analytical run time of 13 s) [49] Liquid handler [50] Commercialization/ Standardization 7-Lab tacrolimus unification [52] 3-Lab cyclosporine A, tacrolimus, and sirolimus unification [53] Much of these DBS validation studies involve the deposition of venous blood from a collection tube onto the paper. Two recent studies evaluated capillary blood from a finger stick.…”