The AA4.1 monoclonal antibody specifically recognizes the Early B Lineage antigen which is also known as CD93, AA4 antigen, Ly-68, and Complement component C1q receptor (C1qRp). This 130-140-kDa type I transmembrane glycoprotein is expressed on immature B lymphocytes in the adult bone marrow and on hematopoietic progenitors and stem cells in adult bone marrow, fetal liver, and embryonic yolk sac. Although CD93+ cells are most plentiful in adult mouse bone marrow, a smaller number of CD93+ cells which express lower CD93 levels can be detected in the adult spleen using bright fluorescent conjugates of the AA4.1 antibody or an amplified indirect immunofluorescent staining procedure. It has been observed that the staining pattern of the 493 monoclonal antibody is similar to that of the AA4.1 antibody, in that both antibodies precipitate molecules of the same molecular weight. Staining with the AA4.1 antibody is not blocked by the 493 antibody. These results suggest that the antibodies recognize separate epitopes on the same Early B Lineage antigen.
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.