Flexible automated platform for blood group genotyping on DNA microarrays

The poor suitability of standard hemagglutination-based assay techniques for large-scale automated screening of red blood cell antigens severely limits the ability of blood banks to supply extensively phenotype-matched blood. With better understanding of the molecular basis of blood antigens, it is now possible to predict blood group phenotype by identifying single-nucleotide polymorphisms in genomic DNA. Development of DNA-typing assays for antigen screening in blood donation qualification laboratories promises to enable blood banks to provide optimally matched donations. We have designed an automated genotyping system using 96-well DNA microarrays for blood donation screening and a first panel of eight single-nucleotide polymorphisms to identify 16 alleles in four blood group systems (KEL, KIDD, DUFFY, and MNS). Our aim was to evaluate this system on 960 blood donor samples with known phenotype. Study data revealed a high concordance rate (99.92%; 95% CI, 99.77%-99.97%) between predicted and serologic phenotypes. These findings demonstrate that our assay using a simple protocol allows accurate, relatively low-cost phenotype prediction at the DNA level. This system could easily be configured with other blood group markers for identification of donors with rare blood types or blood units for IH panels or antigens from other systems.