ADAMTS13 proteolysis of VWF from 4 unrelated patients with type I VWD compared with a healthy control. (A) Multimer analysis showing the multimer profile of the VWF in each cryoprecipitate before (T = 0 hours) and after (T = 8 hours) incubation with cryodepleted plasma containing ADAMTS13. M, A, B, and C indicate patients with type I VWD; N represents a healthy control. (B) Densitometric scans of the lanes in A. Individual panels correspond with individual lanes. At T = 8 hours, the loss of HMW multimers, gain of LMW multimers, and quantitative increase in the triplet bands are apparent as proteolysis proceeds. The horizontal axis is optical density: 0 = black, 300 = white.