<p>Immature platelets represent the youngest platelets in circulation. They are also present in all platelet units given to patients. However, there is limited knowledge of what occurs to these platelets during routine blood manipulation at transfusion facilities. We aimed to establish quantitative changes in immature platelets during routine volume reduction procedures. Platelet units were centrifuged followed by volume reduction and resuspension in a smaller volume. Centrifugation and hemoconcentration resulted in a significant increase per milliliter in platelets and immature platelets. Analysis of total counts of platelets and immature platelets after manipulation showed that these were conserved without significant changes. Furthermore, the ratio of platelets to immature platelets after manipulation also remained unchanged. Importantly manipulation did not seem to affect viability of immature platelets. These results indicate that centrifugation and hemoconcentration preserved immature platelets in platelet units.</p> Graphical Abstract <p>Description of experimental methodology used to hemoconcentrate platelet (PLT) units. Platelet counts with absolute immature platelet count were obtained before manipulation of PLT units and post-hemoconcentration of both the resulting concentrated PLT units and the corresponding supernatant extracted during hemoconcentration. Results indicated that hemoconcentration did not result in losses of immature platelets since these were preserved in the hemoconcentrated units with few lost during processing.</p> <p></p>