Validity of Chromium-51 Labelling of Human Erythrocytes as an Assay for Their Survival after Photodynamic Therapy in Vitro for Blood Sterilization

Abstract

Labelling of human erythrocytes with ⁵¹CrO₄²⁻ is used as an assay for survival of red blood cells (RBC) in the circulation. To ascertain whether the assay is valid for RBC treated with sulfonated aluminium phthalocynine and red light, a procedure designed for viral deactivation in RBC concentrates, we followed release of ⁵¹Cr and haemolysis after photosensitization. The results shows that ⁵¹Cr release does not occur until about 3 h prior to haemolysis. The absence of ⁵¹Cr loss from cells not committed to lysis indicates that the label technique is valid for determination of survival of photosensitized RBC in the circulation.