hi,

Have you isolated RNA from plasma using a specific kit or TRiZOL method? Since, RNA from plasma and serum are fragmented RNA or small RNA, mainly miRNA, and either bound to proteins or contained inside extracellular vesicles. So, here the Isolation method is very important.

Now, for cDNA synthesis, prefer miRNA specific cDNA kit to maximize your miRNA conversion to cDNA.

Based on the cDNA synthesis brand, you will decide the qRT-PCR master mix because very few kits (especially the Qiagen kit) found to be compatible with SYBr, otherwise, Thermo needs a Taqman probe.

Regards

Saurabh

Saurabh Mandal I am isolating miRNA from plasma using the Qiagen miRNEASY serum/plasma Advanced Kit. Once my isolation is done, I am looking to fix a constant amount of RNA for my cDNA reaction (miRNA specific), I am looking for a way to do this as nanodrop based results are very variable and it is becoming difficult to get equal amount of miRNA for all samples in the cDNA reaction.

Nanodrop is not very reliable for exact quantification. If possible, try QUBIT or similar for accurate quantification.