inert dye for real-time pcr

[jcww99]

I'm looking for an inert dye to add to my colorless real-time pcr
mixes to be able to check the performance of a pipetting robot. Of
course there are commercial solutions like Thermo's Absolute Blue but
these are not an option. Years ago in this group tatrazine was
mentioned as a possible dye. Does anyone know more ????

Thanks to you all

Emilio