Introduction As part of the process to improve the safety and quality of the platelet supply, the NBS is evaluating the use of platelet storage media (PSM). The objective of this study was to produce a platelet concentrate (PC) containing 70% SSP+ and 30% plasma, whilst maintaining platelet yield, and to evaluate their in vitro function. Study Design. Buffy coats were prepared using the standard NBS method and four (ABO matched) were pooled together with 250 mL of SSP+. Centrifugation was performed using optimised conditions for PSM and an Optipress used to express the PC through a Pall Autostop LD filter into a Pall ELX storage bag. Ten PCs were prepared, and platelet quality was assessed using in vitro assays for functionality and activation on days 1, 5, 7 and 9 of storage. Results The assay results were compared to platelets stored in 100% plasma from a previous study. Conclusion Buffy coat derived PC in 70% SSP+ met the required specifications for platelet yield, residual leucocyte count, pH and volume. Platelet activation was lower in PCs stored in SSP+ and units stored in SSP+ maintain acceptable in vitro function during storage.