The 5D3/CD338 monoclonal antibody specifically binds to an epitope of ABCG2 (BCRP1), a multi-drug resistance protein that is a member of ATP binding cassette (ABC) transporters. It is highly expressed on primitive stem cells as identified by the "side-population" (SP) phenotype. This SP phenotype is based on the efflux of fluorescent dyes such as Rhodamine 123 and Hoechst 33342. The expression of ABCG2 appears to be highly conserved as it has been identified in various species. Studies show that highly purified murine stem cells express BCRP1 mRNA and this expression declines sharply as the stem cells express CD34. The highest levels of BCRP1 mRNA expression have been seen in KDR+ human stem cells. ABCG2/BCRP1 was clustered as CD338 in the HLDA8 workshop.
The antibody was conjugated to an oligonucleotide that contains an antibody clone-specific barcode (ABC) flanked by a poly-A tail on the 3' end and a PCR handle (PCR primer binding site) on the 5' end. The ABC for this antibody was designed to be used with other BD AbSeq oligonucleotides conjugated to other antibodies. All AbSeq ABC sequences were selected in silico to be unique from human and mouse genomes, have low predicted secondary structure, and have high Hamming distance within the BD AbSeq portfolio, to allow for sequencing error correction and unique mapping. The poly-A tail of the oligonucleotide allows the ABC to be captured by the BD Rhapsody™ system. The 5' PCR handle allows for efficient sequencing library generation for Illumina sequencing platforms.
NOTE: The BD Rhapsody Single-Cell Analysis System must be used with the BD Rhapsody Express Instrument.