【Objective】 To identify a case of antibody against highly prevalent antigen through molecular biology technology. 【Methods】 Blood group typing, unexpected antibody identification and cross matching were performed by serological test, and genetic testing of Diego blood group was performed by molecular biology technology. 【Results】 Serological test showed that there was a high prevalence of anti-Di^b in the serum of the patient. Gene sequencing showed that the genotype of the patient was Di(a+b-) . Two cases with Di(a+b-) matched with the patient were screened from 856 blood donors. 【Conclusion】 The combined detection method based on serological test supplemented by molecular biology technology is beneficial to the detection of antibody against highly prevalent antigens, and is of great significance for ensuring the safety of clinical blood transfusion.

【Objective】 To investigate the distribution frequency of RBC rare blood group among blood donors in Chongqing, so as to provide basic data for the establishment of regional rare blood group donor database. 【Methods】 A total of 14 805 voluntary blood donors of Chongqing Blood Center from December 2020 to May 2021 were screened for Jk(a-b-) phenotype of Kidd blood group system by urea hemolysis test and confirmed by saline agglutination test. The indirect anti-globulin test was used to screen the Fy(a-) phenotype of Duffy blood group system, s-phenotype of the MNS blood group system and k- phenotype of Kell blood group system in 1 466 O type blood donors. The polyamine test was used to screen the Di(b-) phenotype of Diego blood group system in 856 voluntary blood donors, and confirmed by anti-globulin test. 【Results】 Among the voluntary blood donors in Chongqing, the proportion of Jk(a-b-) phenotype was 0.0203% (3/14 805). The ratio of both Fy(a-b+ ) and S+ s- phenotype among type O blood donors was 0.136 4% (2/1 466), and k- phenotype was not seen. The proportion of Di(a+ b-) phenotype among 856 blood donors was 0.233 6% (2/826). 【Conclusion】 The distribution frequency of rare blood group antigens in the above five blood group systems in Chongqing voluntary blood donors presents regional characteristics.