About TCR V delta 1
T cell receptors recognize foreign antigens which have been processed as small peptides and bound to major histocompatibility complex (MHC) molecules at the surface of antigen presenting cells (APC). Each T cell receptor is a dimer consisting of one alpha and one beta chain or one delta and one gamma chain. In a single cell, the T cell receptor loci are rearranged and expressed in the order delta, gamma, beta, and alpha. If both delta and gamma rearrangements produce functional chains, the cell expresses delta and gamma. If not, the cell proceeds to rearrange the beta and alpha loci. This region represents the germline organization of the T cell receptor alpha and delta loci. Both the alpha and delta loci include V (variable), J (joining), and C (constant) segments and the delta locus also includes diversity (D) segments. The delta locus is situated within the alpha locus, between the alpha V and J segments. During T cell development, the delta chain is synthesized by a recombination event at the DNA level joining a D segment with a J segment; a V segment is then joined to the D-J gene. The alpha chain is synthesized by recombination joining a single V segment with a J segment. For both chains, the C segment is later joined by splicing at the RNA level. Recombination of many different V segments with several J segments provides a wide range of antigen recognition. Additional diversity is attained by junctional diversity, resulting from the random additional of nucleotides by terminal deoxynucleotidyltransferase. Five variable segments can be used in either alpha or delta chains and are described by TRAV/DV symbols. Several V and J segments of the alpha locus are known to be incapable of encoding a protein and are considered pseudogenes. [provided by RefSeq, Aug 2016]

About PE-Cy7
PE-Cyanine®7 (PE-Cy7, RPE-Cy7) is a far red-emitting tandem fluorophore that combines phycoerythrin (PE) and Cy7. The donor molecule, PE can be excited by the 488-nm blue, 532-nm green, or 561-nm yellow-green laser and and transfers energy to the acceptor molecule, Cy7, which emitts light that can be captured with a 780/60 nm bandpass filter. PE-CY7 has an excitation peak at 565 nm and an emission peak at 778 nm, and is a suitable alternative to PE-Vio®770 and PE-Fire™ 780.