A New Method for Hematopoietic Stem and Progenitor Cell Preparation : Cord Blood Stem Cell Collection Filter System

We developed a new filter system that can trap nucleated cells(NC)and collect them with high viability from human placental/umbilical cord blood(PCB)units. The filter system consists of a filter containing polyethylene terephthalate non-woven fabrics coated with a hydrophilic polymer and two collection bags. PCB used(75.6±21.5ml, mean±SD, n=8)were filtered and rinsed with saline by gravity within 24 hours after collection. Red blood cells(RBC), platelets(PLT)and plasma were passed through the filter and drained into the lower bag. The NC trapped in the filter were reverse washed out with 23ml of recovery solution, flushed out with sterile air, and collected in the recovery bag. Total processing time required was 6.8±6.2 minutes and handling was very simple. Removal rates for RBC and PLT were 96.0±1.9% and 87.5±3.3%, respectively. Recoveries of NC and mononuclear cells(MNC)after filtration were 59.7±8.3% and 80.4±11.2%. The viability of collected cells detected by trypan blue assay was 98.1±1.9%. The recovery of CD 34+cells was 109.9±33.9%. Colony forming cell(CFC)recovery was 74.3±7.5%. The new filter system is efficient for PCB processing with good recoveries of non-adhesive MNC and CFC.