α-Def-1 delays tPA-mediated lysis of fibrin clots. (A) Fibrin was formed as in Figure 2A from fibrinogen supplemented with plasminogen, tPA, and 0-5 µM α-Def-1, and dynamic clot turbidity (A_405nm) was measured. The results shown are representative of 4 experiments. (B) The time to attain 50% lysis of the fibrin clots formed in panel A, defined as the time elapsed from the maximal to the half-maximal A₄₀₅ value (Lys50_MA) (left) and the time from initiation of clotting needed to reduce the maximum turbidity of the clot to the half-maximal value (Lys50_t0) (right), were determined. The mean ± SD is shown. The results shown are averages from 4 experiments. *P < .05, **P < .01. (C) Photographs of residual fibrin taken after lysis was allowed to proceed for 150 minutes. Images were taken with the EVOS FL Auto Cell Imaging System using EVOS software Scan and Stitch function (top). Individual representative images taken at original magnification ×4 are shown (bottom).