The present study aims to investigate the changes in different parameters related to the storage time of red blood cell (RBC) units. Microscopic, flow cytometric, and electrophoretic assessments were employed every few days for 60 days to investigate the alterations in morphology, size, phosphatidylserine (PS) externalization, and membrane proteins over time. Morphological transformation from discocytes to spherocytes progressed as the storage time increased, which was accompanied by an increment of cellular size. However, this storage period did not result in the externalization of significant amounts of PS (p > 0.05). Mean Fluorescence Intensity (MFI) values increased by 11% to 23% between days 21 and 35 compared to the day 1 sample (p < 0.001). By day 60, the MFI decreased to about 70% of the day 1 sample. The analysis of membrane proteins' distribution showed a significant drop in band 3 expression after 35 days (p < 0.05 and 0.001 on days 42 and 60, respectively); however, no significant change was observed up to five weeks (p > 0.05). The inconsistency observed between Eosin-5-Maleimide (5-EMA) binding and the relative band 3 content could be due to additional accessibility of 5-EMA to hidden domains of other membrane proteins on RBCs as a result of increased mean corpuscular volume (MCV) and changes in morphology. Overall, our present study represents a step-wise and time-dependent series of events that progressively affects stored RBCs.

本研究旨在研究与红细胞 (RBC) 单位储存时间相关的不同参数的变化。显微镜、流式细胞术和电泳评估每隔几天进行一次，持续 60 天，以研究形态、大小、磷脂酰丝氨酸 (PS) 外化和膜蛋白随时间的变化。随着储存时间的增加，椎间盘细胞向球形细胞的形态转变发生，并伴随着细胞大小的增加。然而，这个储存期并没有导致大量 PS 的外化 ( p  > 0.05)。与第 1 天样本相比，第 21 天和第 35 天之间的平均荧光强度 (MFI) 值增加了 11% 至 23% ( p < 0.001)。到第 60 天，MFI 下降到第 1 天样本的 70% 左右。膜蛋白分布分析显示 35 天后带 3 表达显着下降（第42 天和第 60 天分别为p  < 0.05 和 0.001）；然而，在长达五周的时间内没有观察到显着变化 ( p  > 0.05)。在 Eosin-5-Maleimide (5-EMA) 结合和相对带 3 含量之间观察到的不一致可能是由于平均红细胞体积 (MCV) 增加导致 5-EMA 对 RBC 上其他膜蛋白的隐藏域的额外可及性) 和形态变化。总的来说，我们目前的研究代表了一系列逐步影响储存的红细胞的时间依赖性事件。