Mean cell volume measurement on Sysmex XE series instruments using the RPU-2100 diluent system: how external quality assessment works to provide more accurate MCV results and potentially benefit patient management

A key function of external quality assessment (EQA) is to provide an overview of method and instrument performance. EQA schemes, with their unique access to participants’ data, are ideally placed to work with expert users of laboratory equipment and instrument manufacturers to improve performance in laboratory medicine. The UK National External Quality Assessment Scheme for General Haematology (UK NEQAS (H)) and Sysmex UK, in co-operation with Sysmex Europe and University College London Hospital (UCLH), have investigated mean cell volume (MCV) values generated by analysers in the Sysmex X-Class grouping for UK NEQAS (H) full blood count (FBC) surveys, connected to RPU-2100 diluent production units. The RPU-2100 unit uses a demineralised water supply to dilute concentrated CELLPACK reagent to 25 times its volume and then directly supplies up to four connected XE series analysers. This gives the user the benefits of not having to stop the analysers to change the reagent as well as reducing the storage space required for CELLPACK reagent kegs and limiting the manual handling required to move the reagent around. The investigation …