Our office is moving! Effective 11/5/21, O’Brian & Associates, P.S. will be located at 16650 NE 79th Street, Suite 200, Redmond WA 98052. Just two blocks away from our present location. We are now offering in-office consultations, as well as both Zoom Meeting and telephone consultations.


A paternity test using blood or tissue taken from the child, the mother and the possible father is 90 to 99 percent effective. Ultimately, the test will rule out whether a particular man is the father of a child. In some cases, more than one man may be required to take a paternity test.

Blood tests have been used since the middle point of the 20th century. In 1970, a new test used antigens in white blood cells, or Human Leukocyte Antigens, to determine if a man was likely to be the father. However, a DNA test must typically be done in conjunction with a blood test to confirm who the father of a child may be.

DNA testing is considered to be solid evidence of paternity. The DNA of a child will be a combination of the mother's DNA and the father's DNA. If a child has two or more probes that are not a direct match of the father's probes, a particular man can be ruled out as the father. If a man is determined to be the father of a child through a DNA test, the result is considered to be 99.9 percent accurate.

If a man is considered to be the father of a child, he may be ordered to pay child support. However, he also may have a larger set of parental rights as the child's legal father. An attorney may be able to help a father get all of the rights that he may be entitled to under the law. Conversely, legal counsel may be able to help someone dispute the results of a paternity test if there are questions about the results.