It may be necessary to determine paternity when the father's identity is not known, and there are a few ways to do so. The most common method of determining paternity is to use an official screening in which the DNA is tested, though this is also often the most expensive route. There is also a multi-trait test that takes into account various details, such as blood type and eye color. For those looking to save money, using an at-home paternity test or even a conception calculator can help narrow down the results, though these tests are not always accurate or considered official in court.
When trying to establish paternity in order to get child support or custody, the test is usually ordered by a judge in a court of law. It is often expensive and is not typically covered by insurance companies, but parents looking for child support may find the screening worth the upfront cost. Most states request that an official paternity test be taken before they offer state aid to single parents, in which case the state will likely pay for it. This screening usually uses hair, semen, or cheek cells, to name a few sources of DNA, when determining paternity. To remain official and valid in court, only an approved laboratory technician can collect and handle the DNA.
Some people cannot afford to take this test, and perhaps do not qualify for state aid so they would have to pay for it on their own. In such cases, home paternity tests may be considered, which is a method that involves collecting a DNA sample and sending it in to the test manufacturer to be analyzed. Since the DNA is not within a laboratory technician's possession at all times, it will not be accepted in court, but it is helpful for satisfying personal curiosity. Another test that can be accomplished at home is an online calculator that uses the date of the last menstrual period to narrow down a possible conception date. This may not be official, but it can help most women in determining paternity since it makes it clear when her most probable ovulation days were.
There is another way of determining paternity without using DNA, as some tests use certain characteristics instead. Finding out and comparing the blood type of the child, the mother, and the father can help narrow down the results, as certain blood types combined can only result in specific blood types. For example, two people with O blood type can only have a child with O blood type, as well, so if the child has AB blood, the paternity should be questioned. The same goes with eye color, as some combinations cannot produce certain colors. While this method of determining paternity is usually free, it cannot produce definitive results, so it is not typically used in a court of law.