Diminished fibrin generation and platelet thrombus formation in Gα₁₃^{fl/fl–PF4-Cre}mice in vivo. Intravital microscopy was used to monitor fibrin generation and platelet thrombi in vivo after laser-induced cremaster arteriole wall injury in Gα₁₃^fl/fl control and Gα₁₃^{fl/fl–PF4-Cre} mice. (A) Western-blot analysis of Gα₁₃ expression in platelets from Gα₁₃^fl/fl and Gα₁₃^{fl/fl–PF4-Cre} mouse. (B-C) The median integrated (Int.) fluorescence (FL) signals of fibrin (B) and platelets (C) from 25 thrombi in Gα₁₃^fl/fl control mice and from 27 thrombi in Gα₁₃^{fl/fl–PF4-Cre} mice are shown as a function of time. (D-E) The median of the total FL detected over time for fibrin (D) or platelets (E) is shown, calculated by integrating the area under the curve. (F) Representative images of fibrin generation (green) and platelet thrombi formation (red) and merged images. ***P < .001. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.