About CCR5
This gene encodes a member of the beta chemokine receptor family, which is predicted to be a seven transmembrane protein similar to G protein-coupled receptors. This protein is expressed by T cells and macrophages, and is known to be an important co-receptor for macrophage-tropic virus, including HIV, to enter host cells. Defective alleles of this gene have been associated with the HIV infection resistance. The ligands of this receptor include monocyte chemoattractant protein 2 (MCP-2), macrophage inflammatory protein 1 alpha (MIP-1 alpha), macrophage inflammatory protein 1 beta (MIP-1 beta) and regulated on activation normal T expressed and secreted protein (RANTES). Expression of this gene was also detected in a promyeloblastic cell line, suggesting that this protein may play a role in granulocyte lineage proliferation and differentiation. This gene is located at the chemokine receptor gene cluster region. An allelic polymorphism in this gene results in both functional and non-functional alleles; the reference genome represents the functional allele. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2015]

About Alexa Fluor 647
Alexa Fluor™ 647 (AF647, Alexa 647) has an excitation peak at 650 nm and an emission peak at 665 nm, and is spectrally similar to Cy®5 (GE Healthcare), iFluor® 647 (ATT Bioquest), and DyLight™ 650 (Thermo Fisher Scientific). Alexa 647 is commonly used for flow cytometry, microscopy, super-resolution microscopy applications. It is very bright, photostable, and pH insensitive, all of which contribute to sensitive detection while using this dye.