I am doing RT-PCR and i need to detect RNA as low as 10 to the 1 copy number. These are my positive controls as my final detection level will be this low in my serum samples.
You can separately doing cDNA from your RNA, where you can increase the cycle number then you will get a good yield in final cDNA. That will be easy for detection.
In another way, The level of Detection in RT-PCR is limited to the assay design. Sometimes a low amplification remain below the threshold level or in RT-PCR curve noise level.
So, try to select a kit with lower level of detection (High sensitive kit) or decrease the threshold level or cut-off below by comparing your sample with a Blank or Negative sample. So, comparing the curve with a Black sample will help to understand about the amplification of your low level of RNA sample.