Abstract

The production and certification of ERM-DA470k/IFCC, a new serum protein reference material intended to replace ERM-DA470, is described. Serum was produced from blood collected in 6 blood collection centres according to a procedure ensuring that it was obtained from healthy donors, and that the lipid content of the serum was low. The serum was processed in 5 batches, and then pooled, spiked with B2M and CRP and filled into vials (1 mL serum per vial). The serum was lyophilised in the vials and afterwards closed with rubber stoppers and screw caps and stored at -70 °C. The stability and homogeneity of the material were assessed for 14 proteins, including CER and B2M. ERM-DA470k/IFCC was characterised for 12 proteins using the reference material ERM-DA470 as calibrant. This was achieved using a value transfer protocol that can be considered as reference procedure. The techniques used to measure the protein concentrations were immunonephelometry, immunoturbidimetry, and for ALB also visible spectrometry. The measurements were performed with different platform/reagent combinations (Abbott Architect, Beckman Immage, BN II and BN ProSpec, different Hitachi instruments, Roche Integra, LX 2200, and Olympus AU640). In total 18 laboratories participated in the value assignment, 4 using open value transfer procedures, 12 using closed value transfer procedures, and 2 using both open and closed procedures. The results show that open and closed value transfer procedures give very similar results, and lead to robust values for A2M, AAG, AAT, ALB, C3c, C4, HPT, IgA, IgG, IgM, TRF, and TTR.