But he says the abuses continue and that is a major blot (stain) on the new government.

VOA: standard.2009.06.21

Immaculate means "without stain."

无原罪就是“无污点“的意思“

耶鲁公开课 - 新约课程节选

Now if I can stain in some way, if I can somehow label the DNA fragments that I'm interested in, I could find out where those fragments are on this gel.

那如果我有某种染色的方法,对我感兴趣的DNA片段进行标记,我就能知道这些片段在凝胶板上的位置

耶鲁公开课 - 生物医学工程探索课程节选