RESUMEN
<p><b>OBJECTIVE</b>To compare the characteristics of immunomagnetic beads and hespan precipitation for isolation of mononuclear cells (MNCs) from umbilical cord blood and try to find a better isolation method for MNCs.</p><p><b>METHODS</b>Fifteen umbilical cord blood samples from healthy parturiens were collected between December 2007 and March 2008. MNCs were isolated using hespan precipitation and CD133 immunomagnetic beads, respectively. MNCs were identified using the surface marker CD34 by flow cytometry on the 30th of primary culture. Growth conditions and morphologic changes of primary cells were observed by an inverted microscope.</p><p><b>RESULTS</b>The number of MNCs from umbilical cord blood isolated by hespan precipitation (15.23 +/- 4.30 x 10(6)/mL) was significantly greater than that by CD133 immunomagnetic beads (0.066 +/- 0.027 x 10(6)/mL) (p<0.05). The MNCs isolated by hespan precipitation suspended at the culture medium and their growth was slow after passage. The growth of MNCs isolated by CD133 immunomagnetic beads was kept in a good condition. The CD34 positive rate of MNCs isolated by hespan precipitation and immunomagnetic beads was 10.1% and 0.5%, respectively.</p><p><b>CONCLUSIONS</b>The hespan precipitation is an effective method for MNCs isolation from human umbilical cord blood, but with a cell growth condition below the mark. The MNCs isolated by CD133 immunomagnetic beads are in a high purity quotient.</p>