Application of a time-resolved fluoroimmunoassay for the analysis of normal prion protein in human blood and its components

Backround and Objectives: To quantify the cellular isoform of prion protein (PrPc) in human blood using a new time-resolved dissociation-enhanced fluo roimmunoassay (DELFIA(R)). Materials and Methods: The DELFIA was optimised for human blood samples and applied to isolated cell and plasma fractions from blood donations. The ph ysicochemical properties of PrPc were analysed. Results: 26.5% of blood PrP c was associated with the platelet fraction, 0.8% with polymorphonuclear le ucocytes, 2.4% with mononuclear leucocytes, 1.8% with red cells and 68.5% w ith plasma (mean values from 4 processed donations). Conclusion: The majority of blood PrPc is found in the platelet and plasma compartments.