Blue SG onTaq qPCR Master Mix (2x), plus ROX Solution provides the same onTaq hot-start SYBR Green I chemistry as E0416 — including optional UNG carryover protection and a blue pipetting-tracking dye — together with a separately supplied ROX passive reference dye. The included ROX Solution adjusts the reference signal for instruments that require it, such as Applied Biosystems cyclers (and optionally Stratagene), correcting for well-to-well fluorescence fluctuations. Choose this variant whenever your platform calls for a passive reference dye.