Improved Factor VIII Yield by Instrumented Cryo-Precipitate Harvesting Technique

The present cryo-precipitate manufacturing process has been modified to utilize mechanical and electro-mechanical aids. Up to four bags of plasma are placed in a a rack of special design in which they are frozen and then thawed in a vertical position. Thawing takes place in a 4° C water bath where vibration transmitted through the water causes an increase in precipitate density at the bottom of the bag. Supernatant plasma is then transferred to the satellite bag using an expressor upon which is mounted a photo detector operated shut-off mechanism. In this device a photo cell monitors plasma color as it enters the transfer tube activating a solenoid clamp on the tubing when cryo-precipitate reaches the transfer point at the top of the bag. The signal from this detector may also be used to automatically trigger a dielectric heat sealer. An increase in Factor VIII yield has been achieved averaging 14%.