Establishing Paternity: Blood Tests

San Jose Divorce Lawyer

A Quick Science Lesson

Paternity tests using blood samples were first performed in the middle half of the twentieth century. The tests involved comparing blood types of tested parties, which require isolation of blood sera from antigen-challenged individuals that did not posses certain red blood cell antigens. These antigens are protein molecules and may be combined with sugar molecules. They are found in the red blood cell membrane. The sera cause coagulation of red blood cells in individuals that possess that particular red blood cell antigen.

Blood Types

An ABO system is used to categorize blood types. Humans with the A antigen have A blood types, the B antigen have B blood type, both the A and B antigen have the AB blood type, or neither of the antigens have the O blood type. The blood tests work by exclusion. A mother who has type B blood and a father who has type O blood could not have a child with type AB blood.

Advances in Science

A more powerful test was developed in the 1970′s using white blood cell antigens, Human Leukocyte Antigens. The test was able to exclude about 95 percent of falsely accused fathers. Blood types alone cannot determine who the father is, but to determine the biological possibility of fatherhood.

Speak with a San Jose Paternity Lawyer

If you need to determine or challenge the paternity of your child or alleged child, the support of an attorney can help make the process easier for all parties involved. Contact San Jose paternity lawyer Daniel Jensen at 408-296-4100 today.