Methods The cell-free system was prepared by ultracentrifugation of Xenopus eggs and activated by cytochrome C.

方法超速离心制备非洲爪蟾胞体系,胞色C为凋亡体系。

We separated the subfractions of LDL by precipitating method and density gradient ultracentrifugation, and identified the subfraction by electronphoresis and electron microscope.

通过沉淀法分离LDL,然后经过超速离心法分离其亚组分。