In that case,

在此种情况下
we took the gene for the Hepatitis B protein.

我们将乙肝病毒的基因同蛋白质外壳分离
Took it out of the virus completely,

将基因从病毒中完全提取出来
cloned it into a plasmid,

并克隆制成质粒
that plasmid was expressed in a foreign host,

该质粒在外来宿主中表达
in this case it was expressed in yeast cells.

此例中质粒在酵母细胞中表达
Yeast cells were grown in large numbers with this plasmid inside,

体内携带这种质粒的酵母细胞大量增殖
they expressed the plasmid

它们表达质粒
and so you made Hepatitis B surface antigen

因此乙型肝炎表面抗原不是在人体内
not in people but in cell culture

而是在细胞培养环境下
where it was not normally formed.

以非正常方式形成的
Then that subunit was purified and formulated into the vaccine,

然后亚基被纯化出来并制成疫苗