How much template can I use in the reaction and what is the maximum volume of template that can be used in the QuantiTect Kits?
FAQ ID -1086

Even when detecting low-abundance targets, we recommend using no more than 500 ng/reaction of DNA (for PCR kits) or RNA (for RT-PCR kits). Generally, 1–100 ng template should be sufficient and for abundant transcripts as little as 1 pg can be used.

Template purity is important if large volumes of low concentration template are to be added to the reaction. Using DNA or RNA purified with QIAGEN products, the template can contribute up to 40% of the final reaction volume as long as the recommended template amounts are not exceeded. If cDNA from an RT reaction is used as template, the volume of undiluted RT reaction added should not exceed 10% of the final PCR volume.