To do that, Costello's co-lead researcher took samples of bacteria from mothers and babies immediately before and after birth.

VOA: standard.2010.06.30

There's another sample which is in Russia, part of the former Soviet Union, where there are samples that were stored.

另一个样本在俄罗斯,前苏联的一部分,那也有储存的样本

耶鲁公开课 - 生物医学工程探索课程节选

There's another sample which is in Russia, part of the former Soviet Union, where there are samples that were stored.

另一个样本在俄罗斯,前苏联的一部分,那也有储存的样本

耶鲁公开课 - 生物医学工程探索课程节选