人胰岛素功能基因转移中的除泡技术

The lipid-stabilized microbubbles appear as a milky white
suspension floating on the top of a layer of liquid containing
unincorporated plasmid DNA. The subnatant was discarded,
and the microbubbles were washed three times with PBS to
remove unincorporated plasmid DNA. The mean diameter and
concentration of the microbubbles in the upper layer were
measured by a particle counter (Multisizer III; Beckman
Coulter). The mean diameter and concentration of the microbubbles
were 1.9 0.2 m and 5.2 0.3 109 bubbles per ml,
respectively. The amount of plasmid carried by the microbubbles
was 250 10 gml.