A device and kit and method for controlling coagulation in a blood sample. The coagulation controlling agent is at least one of citrate, a protamine salt, its homologs and derivatives, benzamidine, or para-aminobenzamidine. Additives such as water soluble polymers and sugars are also contemplated. The device and kit comprise a container that contains an effective amount of thrombin and a coagulation controlling agent. The method combines thrombin and a coagulation controlling agent to stabilize thrombin or accelerate its activity in a blood sample.
