Figure 1. Schematic of Bone Marrow Harvest and Screens.

The bone marrow aspirate collected from donors is hooked up typically to two filters called screens connected in series ( 500 μM first followed by 200 μM) to filter out particulate matter including spicules, clots and tissue fragments. The filtrate is collected for infusion ( processed marrow). The marrow screens are then made available to research laboratories with the entry port and exit connected to each other.