DusQ21 CPG 500, identical to QSY21, is a quencher for the dyes in far red region of the spectrum. The dye is a xanthene derivative, unlike DusQ1 or DusQ2, that are azo dyes. It has a high extinction coefficient, and provides an outstanding quenching efficiency.
AxisPharm offers 4000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.