ABSTRACT
<p><b>OBJECTIVE</b>To investigate the serological and molecular biological identification of B(A) blood group and its reasonable method of blood transfusion for patient with B(A) blood group.</p><p><b>METHODS</b>The blood group of patient was detected by serological method, at the some time, the genotype of patient was detected by using the ABO-TYPE Variant kit and sequence analysis of 6 and 7 exons in ABO gene; the washed O red blood cells were used to cross matching blood of difficultly matching blood by the three step analysis method.</p><p><b>RESULTS</b>The A weak and B strong agglutination were found in positive type, and A1C(3+), BC(-) were observed in negative type; the molecular biological identification showed B(A)04, 640 A > G; the matching blood main side of washed O red blood cells displayed no agglutination.</p><p><b>CONCLUSION</b>The identification and analysis of rare blood or subtype should be very careful; if necessary, the molecular biological detection should carried out; the blood transfusion for patient with rate blood group or subtype should be safe, correct and reasonable.</p>