With the help of various tests (tensile strength, distribution in cancellous bone blocks, thrombin release from standard clots), the importance of mixing the solutions of the fibrin sealant system was demonstrated and an optimal mixing ratio of one to one was identified. Different application techniques are discussed. The spraying technique, which produces rapid hemostasis, is reviewed in detail. As further advantage, the resulting sealant film is thin. This appears important for promoting wound healing.