HI Neus, I believe your end goal for this experiment is to quantify your gene from the total RNA. So amplifying RNA wouldnt really tell you the exact concentration of RNA. Another bottleneck here is that RNA cannot be amplified in contrast to DNA which is easily possible through PCR. However, if you want to have more RNA you will have to begin with more cells or starting material and then use a good purification kit. I suggest using Invitrogen RNA purification kit to ensure good yields. Or else, if you really want more of your RNA, then you can try performing reverse transcription and PCR and while in PCR have a forward primer with T7 RNA polymerase promoter and then you can invitro transcribe your DNA product. That way you will have more of your RNA product. I hope this helps !

You can also look at these kits - http://www.nugeninc.com/nugen/index.cfm/products/cs/microarrays-and-qpcr/ovation-amp-v2/

Hi and thx for your answers! The problem I have is that I extract RNA from a small part of living organism, and it's very difficult to get samples, so my total amount is very low. I'll try to do RT PCR and see if I get enought cDNA for the real times. And the kit you've shown me looks pretty good, I'll talk with my supervisor about that! Thanks a lot :)!