Recently , I extract RNA from nucleus pulposus cells cultured in alginate beads,the alginate beads were cultured in 24 well plate, with 5 beads in each well.the density of the cells in the alginate beads is 1million/ml .After dissolving the beads, centrifugation,and then washed with PBS twice, I use trizol to extract the RNA, however,the OD260/280 always about 1.2~1.3, could someone give me any suggestion? Thank you for your help!