As an aside, do you know that Sda was originally named Sid? It was named this after Sid Smith, who used to be the janitor at the Medical Research Council's Blood Group Unit, when it was in London, as he had the strongest expression of the antigen at the time it was identified. In those days, antigens and antibodies were usually named after the first two letters of the surname of such a person, but Sm was already being used for the antigen within the Scianna Blood Group System, that is now known as Sc1, so they named it Sid!!!!!!!!!! I love these "Oh, by the way...." stories! Thanks! Donna