Novel Rh antigen-typing workflow. (A) Diagrammatic representations of the RHD and RHCE genes, the binding positions of array probes are indicated in red. The probes spanning RHD are used for RHD copy number assessment and for RHCE: for example, the probe for typing variant NM_020485.5:c.307C>T, which is used for C/c typing. (B) Results obtained for 2682 Dutch donor samples binned by RHD median copy number/probe set intensity ratio (log2), demonstrating that clear resolution of RHD copy number for each individual can be achieved by using the array. (C) Genotype call plot for the C/c antigen variant NM_020485.5:c.307C>T in the RHCE gene. Samples are colored by array-determined RHD copy number to allow visualization of the intensity shift caused by cross-binding of RHCE probes to RHD. Segregating samples in this way allows for accurate genotypes to be called. (D) Improvement in Rh(C/c) and Rh(E/e) antigen-typing concordance resulting from application of the novel genotyping algorithm.