nice paper, dealing this subject

http://www.biotechniques.com/BiotechniquesJournal/2012/May/Simplified-and-versatile-method-for-isolation-of-high-quality-RNA-from-pancreas/biotechniques-330537.html

The main problem is not the RNA extraction method, but getting intact RNA into lysis buffer. If you lyse the pancreas as a whole, the RNase content of the non-endocrine component of the pancreas (part of its normal activity is to digest RNA!) will trash the RNA very quickly. The key for you will be to get intact intact islets or at least islet cells while keeping everything cold throughout the procedure. Once you get those into RNA lysis buffer (e.g. Qiazol/Trizol), the downstream extraction/kit is a question of budget, yield, application etc. I use Zymo DirectZol, which avoids a phase-separation step - you add Ethanol to the Qiazol and load straight on the column. It is relatively cheap and works very well for cell lines and sorted cells/organoids. For whole tissue you are always better off with a chloroform step, but can use the same kit afterwards.

Good luck!

Thank you very much for your answers!!! I tried by separating isolated ioslets with a syringe in TRIZOL and it works also vrey well!

Regards

I failed to obtai RNA post Ficoll seperation of Islets. I used 300 islets and Zymo columns. I wonder if Islets in the Tri Reagent needs to be homegenized? Can anyone kindly answer this? 

Thank you in advance

I've done a few RNA isolations from mouse islets now and I'm using Trizol reagent, combined with vortex and passing through a 30G needle. After the phase separation i use Qiagen columns (RNeasy micro kit). Starting material is as few as 50 islets and I get some RNA yield.