Figure S2 Effect of GSNO on fiber fluorescence and fiber diameter. Human fibrin clots were prepared and imaged as described in methods. Panels A-E show binarized (BW theshold = 27au) multiphoton images of fibrin clots incubated with GSNO (0,1,1.7,2.5,3.75 mM, respectively). Panels F,I,L show fiber diameter information, where each panel consists of three plots (top to bottom), diameter histogram, normality plot and normal or bimodal fit to the distribution; panels G,J,M show fiber fluorescence distributions; panels H,K,N show plots of fiber diameter against fiber fluorescence, for clots prepared with 0,1,2.5 mM GSNO, respectively. The diameter distribution in control clots was not normally distributed. A bimodal fit to the data found a value of 761.9 nm to be the threshold between thin and thick fibers. Solid lines are the mean value for the distribution. Dashed lines show the control threshold value. 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