The invention provides a system for preparing an autologous solid-fibrin web suitable for regenerating tissue in a living organism. The system includes a sealed primary container containing a separation medium and a low-density high-viscosity liquid. The separation medium is capable of separating red blood cells from plasma when the container contains blood and is centrifuged, and the primary container has a first pressure. The system further includes a sealed secondary container containing a calcium-coagulation activator. The secondary container has a second pressure that is less than the first pressure. The system also comprises a transfer device including a cannula having a first end and a second end. The first and second ends are capable of puncturing the sealed primary and secondary containers in order to provide fluid communication between the first and second containers. The low-density high-viscosity liquid of the primary container is capable of blocking flow through the cannula upon entering therein.