how do you separate foetal and maternal cells?

Question: how do you separate foetal and maternal cells?
- Keywords:
  cell,
  fetal,
  maternal,
  mother
Asked by theapo0408 to Chris on 20 Jun 2013.
- Chris Whittle answered on 20 Jun 2013:
  
  You don’t need to separate them as they are naturally separate anyway. If they were mixed together for some reason you wouldn’t be able to separate them, unless you were having a male baby, as you could look at the difference in the sex chromosomes.

Question: how do you separate foetal and maternal cells?