Check for RNA integrity. If denaturation is prominent, then I believe it won't be of any use.

Thank you Carl. The main trouble is that we are going to receive those samples and need to know how we should treat them before arriving here. I have read some papers but they show contradictory views and most of them suggest white blood cells separation before adding RNAlater (for example). For this particular case, people who is sending the samples, cannot separate white cells and RNAlater requires small volumes of blood to correctly operate. We are going to do a test with control samples here, I hope this helps. Greetings. 

RNAlater, actually, should have been placed as soon as samples were taken. Nonetheless, upon receiving samples, you can perform the separation then proceed with RNA extraction. If you will proceed with your microarray experiments at once, the RNAlater may not be needed anymore.

Also, still check for your RNA integrity before moving forward to avoid data misinterpretations.

Hi Carlos,

have you tryied this? PAXgene Blood RNA Kit IVD - QIAGEN

we send the pax gene tubes to the patient so the blood is collected directly on the right tube.

Very convinien!

Michela

Thank you so much Carl.

Hi Michela,

Thanks for your time. I have not tried by PAXgene, I have by now RNeasy mini kit. I will check for the kit availability. All the best,

Carlos.

I think you should use the PAXgene Collection tubes. Eukaryotic RNA half-life is about 30 min, varying greatly between different genes. Storing your live cells in RT in a tube for one day will seriously change the RNA composition. Even if your RNA integrity looks ok, the RNA expression will no longer represent the situation when the blood was drawn. PAXgene tubes "freeze" the RNA expression profile seconds after blood is drawn. I recommend you read this publication:

http://www.ncbi.nlm.nih.gov/pubmed/14659918

Henrik

Thank you so much Henrik! I agree with you guys, I have to get PAXgene system. Greetings!