Method and apparatus for inactivation of biological contaminants using photosensitizers

A method of inactivating pathogens in red blood cells which may contain pathogens comprising:

• expressing plasma from a unit of whole blood to create a plasma reduced red blood cell containing product;
• adding an additive solution containing riboflavin and a first quencher to the plasma reduced red blood cell containing product;
• illuminating the plasma reduced red blood cell containing product and additive solution for a time sufficient to inactivate any pathogens contained therein;
• and
• storing the irradiated red blood cells in a solution useful for storing blood components which may contain a second quencher.

A method for quenching side reactions of a pathogen inactivating compound in a biological fluid containing blood or blood products as well as pathogens comprising the steps of:

• treating the biological fluid with a pathogen inactivating compound wherein the pathogen inactivating compound comprises riboflavin;
• adding to the biological fluid and riboflavin a quencher in an amount sufficient to reduce the level of side reactions without interfering with the inactivation of pathogens by riboflavin;
• and
• exposing the biological fluid and riboflavin and quencher to light of a sufficient wavelength to inactivate any pathogens contained in the biological fluid.