Abstract: Objective Identification of a rare blood type of Di(a+b-) with anti-Dib antibody by serological and molecular biology technique. Methods The patient's blood type, direct anti-globulin test, and irregular antibody screening and identification were performed by serology means. DNA sequencing was used to identify the Diego blood type. Results The patient has irregular antibodies against highly prevalent antigens. DNA sequencing confirmed the rare Di(a+b-) blood type. Conclusion Blood typing by DNA sequencing is pivotal for identification of antibodies against highly prevalent antigens.

Key words: Rare Di(a+b-) blood group, Anti-Dib antibody, Genotyping