What is the difference between AB Negative & AB Positive??

Question: What is the difference between AB Negative & AB Positive??
- Keywords:
  blood group,
  blood type,
  negative,
  positive
Asked by patrycjasiwek to Andrew on 19 Jun 2013.
- Andrew Swale answered on 19 Jun 2013:
  
  The negative and positive part refers to the absence or presence of something called ‘Rh antigens’
  
  This link is really good for explaining all about blood types 🙂
  
  http://en.wikipedia.org/wiki/Blood_type

Question: What is the difference between AB Negative & AB Positive??