5-TAMRA-PEO3-amine (Tetramethylrhodamine-PEO3-amine) has a long water-soluble PEG spacer separating the dye and the amine functional group. The dye can be coupled to activated carboxy groups or sulfonyl chlorides.    &lamba;Ex/&lamba;Em (MeOH) = 544/571 nm  Dark purple solid soluble in DMSO, DMF, or H2O  Store at 4°C and protect from light  C37H42F6N4O11  MW: 832.74