Can you tell paternity by blood type?

Blood type alone cannot definitively determine paternity. While blood type can exclude potential fathers, it cannot positively identify a father. There are multiple blood types, each with different antigens present on red blood cells. A child inherits one blood type from each parent, so if a potential father's blood type is not compatible with the child's, he can be excluded as the father. However, if a potential father's blood type is compatible with the child's, it does not necessarily mean he is the father, as other men with the same blood type could also be potential fathers.

Paternity testing involves analyzing DNA, typically through genetic testing, to determine the biological father of a child. DNA testing compares the DNA of the child, the mother, and the alleged father to determine if the alleged father is the biological father. DNA testing is highly accurate in determining paternity and can provide conclusive results in most cases.