Effect of desialylation in vitro on platelet survivals and the effect of DANA on the survival of platelets in mice after refrigerated storage. (A) Flow cytometric analysis of β-galactose or β-GlcNAc exposure on platelet surfaces, as detected with ECL or s-WGA FITC-labeled lectins. Lectin binding to fresh mouse platelets in the presence and absence of α2-3,6,8,9-Sialidase from A ureafaciens (Neu) at the indicated concentrations (n = 5). (B) Flow cytometric analysis of β-galactose or β-GlcNAc exposure on mouse platelet glycoproteins, as detected above in the presence (Neu) and absence (Control) of 10 mU of α2-3,6,8,9-Sialidase (Neu) and the competitive sialidase inhibitor DANA (Neu + DANA; n = 4). (C) Untreated CMFDA-labeled platelets (Control), platelets treated with sialidase (Neu), or sialidase and the competitive inhibitor DANA (Neu + DANA) were infused intravenously into WT mice (10⁸ platelets/10 g of body weight). Blood was drawn at the indicated time points, and platelets were analyzed by flow cytometry. Results are presented relative to fresh room temperature platelets. Data are mean percentage CMFDA-labeled platelets ± SEM. Each point represents 8 mice. (D) Effect of 1mM DANA on the amount of galactose detected by the ECL assay in the stored and rewarmed platelets just before their injection into recipient mice. (E) Survival of mouse platelets stored for 48 hours by refrigeration in the absence or presence of 1mM DANA in the storage solution. The survival of freshly isolated platelets is shown for comparison (n = 7).