A rubella antibodies test is used to detect antibodies in the blood that are made by the immune system to help kill the rubella virus. The presence of certain antibodies in the bloodstream means a past or recent infection or that you have been vaccinated against the disease. A rubella antibodies test is usually done for a woman who is or wants to conceive a baby to determine whether she is at rubella risk. Rubella antibodies in the blood can be detected by use of several laboratory methods. Enzyme-linked immunosorbent assay (ELISA, EIA) is the most commonly used method for detecting rubella antibodies.