R6G (rhodamine 6G) is a yellow emitting xanthene dye. It has been used for DNA sequencing before. Now this dye is often used for qPCR. This is a pure 5-isomer of R6G with azide group.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.