BackgroundAS‐7 is a new alkaline hypotonic red cell additive solution (AS) shown to improve red cell quality during storage compared with AS‐1. We sought to compare red cells stored in AS‐7 with those stored in SAGM using RCC that were either untreated, or washed or irradiated on day 14 of storage.Study Design and MethodsA pooled and split study design was used to produce seven identical RCC (four in SAGM and three in AS‐7). At day 14 following donation, two RCC (one in SAGM and one in AS‐7) were gamma irradiated and three RCC (two in SAGM and one in AS‐7) were washed and resuspended in either SAGM or AS‐7. RCC were sampled for analysis throughout storage and at end of shelf life: day 28 for washed or irradiated and day 35 for untreated RCC.ResultsFor untreated, washed or irradiated RCC, those stored in AS‐7 had lower haemolysis, red cell microvesicles and supernatant potassium content than RCC in SAGM. In addition, ATP levels and pH were better maintained in AS‐7 RCC than in SAGM RCC.ConclusionThese data suggest that the quality of these components may be improved by storage in AS‐7 compared with SAGM.