Hi Mousa,

We are extracting all our microRNAs in Trizol followed by purification on a commercial column from Invitrogen (miRVana kit). If you want to precipitate with isopropanol after TRIZol, you can try to add 2 volumes instead of 1 volume of isopropanol.

Hi Mousa,

We are extracting all our microRNAs in Trizol followed by purification on a commercial column from Invitrogen (miRVana kit). If you want to precipitate with isopropanol after TRIZol, you can try to add 2 volumes instead of 1 volume of isopropanol.

Life Technologies sells this kit, mirVana miRNA isolation kit which allows miRNA enrichment/isolation. However, it also isolates siRNA, shRNA, and snRNA. Therefore, you show perform a small RNA bioanalyser test to assess which small RNA molecules are actually present or alternatively, perform sequencing to determine if miRNA is present as the nanodrop method is not as sensitive as only gives a rough estimate of RNA molecules, and not specifically miRNA but all RNA.

Also depends on your cell type, mirVana may not work for certain epithelial cells. Qiagen also has specific microRNA isolation kit. I agree with Sim Tung, bionalyser for purity check is essential. I've aslo used Trizol for microRNA, works fine, but you do need a few rounds of isopropanol/ethanol washing.

We used to do our small RNA (i.e. miRNAs among others) extractions with miRNeasy mini kit from Qiagen. It works great.

thanks all. Dear Mr Balaz, I want to isolate total RNA containing miRNA.