Scanning electron micrographs of purified and recombinant fibrinogen γ-chain variants. (A) Clot made from purified γA/γ′ fibrinogen. (B) Clot made from purified γA/γA fibrinogen. Both clots were made with final concentrations of 0.7 mg/mL fibrinogen and 1 IU/mL thrombin. Reprinted from Cooper et al³³  with permission. (C) Clot made from purified γA/γ′ fibrinogen. (D) Clot made from purified γA/γA fibrinogen. These clots were made with final concentrations of 180 μg/mL fibrinogen and 0.1 U/mL thrombin. Reprinted from Siebenlist et al,³⁰  with permission. (E) Clot made from recombinant γ′/γ′ fibrinogen. (F) Clot made from recombinant γA/γA fibrinogen. These clots were made with 10 μL of 4.4 μM fibrinogen and 0.9 IU/mL thrombin. Reprinted from Collet et al⁷⁰  with permission. (G) Clot made from recombinant γ′/γ′ fibrinogen. (H) Clot made from recombinant γA/γ′ fibrinogen. (I) Clot made from recombinant γA/γA fibrinogen. These clots were made with 1.0 mg/mL fibrinogen and 0.1 U/mL thrombin. Reprinted from Gersh et al⁷⁶  with permission.