The kit is used to predict human RhD blood type and provide reference for RhD blood type identification by detecting the presence of Exon 1/3/4/5/6/7/9/10 of the human RhD gene and the 845A and 1227A mutations qualitative. The allele names of the results follow the RhD gene naming principles（v6.2 30-SEP-2022） of the ISBT Red Blood Cell Immunogenetics and Blood Group Naming Committee. This kit cannot be used for blood source screening. The RhD gene encoding RhD blood group antigen is located in the short arm of human chromosome 1, with 10 Exons and 9 introns. The length is 57932 bp and it encodes 417 amino acids. Exon deletion, replacement by RHCE gene, and mutations could lead to weaken or deletion of RhD antigens. RhD antigen has strong immunogenicity and is one of the main reasons of hemolytic transfusion response and HDFN.

The designing principle of sequence specific primers polymerase chain reaction (PCR-SSP) is to design primers based on the differences in a certain base of an allele. Specific primers only amplify the corresponding allele and do not amplify other alleles. Therefore, the presence or absence of amplification products is the basis for identifying specific alleles The specific PCR products can be detected by agarose gel electrophoresis. Specific primers, pointing at RhD related gene mutations, deletions, insertions and other information, were designed according to the sequence information published in Genbank database of NCBI.
The internal reference primers were designed based on the sequence of the conserved regions of human genes. Internal reference primer pairs are used to check the amplification effectiveness of the reaction systems. They are coated with specific primers in each reaction well to amplify together.