DNA testing is done to determine some abnormalities in the cell of the individual that can be passed to her offspring. Some series of tests is done by trained professional and the result could take a few days or weeks. It can cost much but the test is reliable and accurate.
My friend had done it right before his husband and she got married. They agreed to do this to make sure that they are capable of bearing a normal offspring. I accompanied them to the physician I know so that they can avail of big discount since this test can really cost a lot.