The current European Pharmacopoeia (Ph. Eur.) Human immunoglobulin for electrophoresis Biological Reference Preparation (BRP) batch 2 was established in 2002 during acollaborative study run by the European Directorate for the Quality of Medicines & HealthCare (EDQM) under the aegis of the Ph. Eur. group of experts 6B. Due to dwindlingstocks of this BRP, the Biological Standardisation Programme Steering Committee decided to endorse a project, BSP123, in order to establish a replacement batch. The project leader forthe study was Dr. Stefan Christians from the Paul Ehrlich Institut (PEI), Langen, Germany. Prior to the start of the collaborative study an enquiry on the medium used for routineanalysis of immunoglobulins by ZE was performed amongst the users of the Human immunoglobulin for electrophoresis BRP. Out of 16 respondents only 2 laboratories reportedto use cellulose acetate as a medium for routine testing (one of them reported the switch to agarose was pending).Similarly to what was done for batches 1 and 2 an immunoglobulin preparation was spiked with albumin, distributed in aliquots of 1 mL and subsequently freeze-dried at the EDQM.The suitability of this batch to serve the intended purpose was assessed in a collaborative study. A feasibility phase at PEI was performed satisfactorily to pre-qualify the newcandidate material. An international collaborative study was then undertaken in order to calibrate the new candidate BRP batch. Participants were requested to estimate the content ofthe main immunoglobulin band obtained by zone electrophoresis using strips of cellulose acetate or agarose gels as described in the Ph. Eur. monographs on immunoglobulin and toexpress this content in per cent of total protein
