Blood Typing
There are four blood groups; A, B, AB & O. All of these may or may not have an Rh antigen attached, thus giving the blood type a positive (+) or negative (-) annotation.
Lessons Related To Blood Typing
There are four blood groups; A, B, AB & O. All of these may or may not have an Rh antigen attached, thus giving the blood type a positive (+) or negative (-) annotation.