RT-PCR low efficiency - (Jan/19/2016 )

I normally use Taqman probes for my RT-PCR, but have recently ordered custom primers for some SYBR green assay. 

I extract my RNA using Promega Relia prep and prior to cDNA synthesis, I perform DNAse treatment using Thermo Fisher's DNA-free kit. Then subsequently I will reverse transcribe a total of 1ug of RNA using Promega's GoScript. Now... to optimise my RT-PCR reaction, I have constructed a standard curve with a 10-fold dilution series of my template. The melt curve analysis shows a single peak for all my primers. But my reaction efficiency is really low (~50-70%). What could be the problem? How can I increase my reaction efficiency? 

What concentration of primers are you using? You could try different primer concentration to have a good efficiency, try to increase/decrease the amount of cDNA you are loading. If everything fails, design new primers and order them. That's the easy solution without wasting too much time and reagents.

Good luck !!